CIRP ANNALS 1993
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STC A |
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A module for the automated planning of grasps in robotized assembly operations
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G. Dini (2)
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STC A, 42/1/1993, P.1
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Keywords: Automatic Assembly, Grippers, Planning |
Abstract : This paper reports on the development of a software module able to
select the surfaces of an object to be grasped by a robot and to
generate the optimal configuration of a two-jaw gripper. The various
aspects involved in the direction of the surfaces for gripping are
analyzed and discussed: surface geometry, orientation, position with
respect to the centroid of the object, etc. In particular, the methods
and the advantages obtained in the application of the fuzzy logic for
the selection of the surfaces that assure a stable and accessible grasp
are described. Furthermore, the methodology adopted for a parametric
configuration of the main features of the gripper is explained. At the
end, some meaningful examples of results are reported and discussed.
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Grasping and walking finger manipulation of objects using four-fingered hand
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N. Brook, M. Shoham, J. Dayan / R. Weill (1)
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STC A, 42/1/1993, P.5
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Keywords: Robots, Grippers |
Abstract : Options for grasping an object are restricted by the surface on which
the object is placed. There is a frequent need therefore, to manipulate
the object from an initial lifting grasp to a final working one. We
present here an algorithm for finding the three-finger force-closured
grasp space of polygonal objects for arbitrarily small friction (certain
particular solutions for smooth objects are also given). Using a
graphical representation of the grasp space we determine conditions for
manipulating an object from one grasp to another with four fingers and
arbitrarily small friction. Planning possibilities for the manipulation
process are also presented.
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A 2-D mapping approach for monitoring and diagnosing the execution of robotic assembly task
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H.A. ElMaraghy (1), A. Syed, H. Chu, W.H. Elmaraghy
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STC A, 42/1/1993, P.9
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Keywords: Robotic Assembly, Diagnosis, Neural-Networks |
Abstract : Assembly task planning is concerned with generating the sequence of
operations and the required detailed execution instructions. Realtime
monitoring, and diagnosing of uncertain events, based on the latest
feedback from sensor (vision, tactile, force, etc.), during robot
assembly tasks
Execution plays a vital role in ensuring a reliable and robust assembly.
This paper presents techniques developed for realtime monitoring of
assembly operations, direction of errors due to parts mishandling such
as incorrect parts manipulation, insertion and placement in the
workspace or due to interference between robots
sharing the workspace. Two-dimensional maps are created bv adaptative
projecting the typically three or more dimensional assembly problems to
a simpler two-dimensional problem space which provides the flexible and
efficient associative properties needed for effective realtime
monitoring and diagnosis. A self-organizing neural network (Kohonen map)
is used for organizing the various inputs regarding parts, tools and
sensors feedback during robotic assembly and diagnosing the sources of
errors. Re-planning of the assembly to recover front errors would then
proceed based on this feedback. The results of this research have been
demonstrated in thee real assembly of a dishwasher power unit.
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Automatic generation of assembly constraints and cooperation task planning
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S.Y. Nof, V.N. Rajan / E. Lenz (1)
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STC A, 42/1/1993, P.13
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Keywords: Assembly Analysis, Multi-Robot Systems, Cooperation, Optimal Planning |
Abstract : Cooperation is considered an essential attribute of intelligent
multi-robot systems. It enhances their flexibility and reliability. The
Cooperation Requirement Planning (CRP) process consists of two steps:
CRP-I for generating the assembly, robot, and cell constraints, and the
cooperation requirements; and CRP-II for performing task assignment,
and generating a consistent and coordinated global plan for task
execution. In this paper, we describe the CRP-I methodology which takes
the assembly and multi-robot cell information to generate the
constraints and the cooperation requirements. For a given assembly, its
geometric model is analyzed to generate the minimal set of geometric
precedence constraints. The geometric, physical, and operational
requirements of the assembly tasks are then matched with the
corresponding capabilities of the various robot sets in a given
multi-robot cell to generate the robot and cell constraints, and the
cooperation requirements. The CRP-I methodology has been implemented
using the ROBCAD^© robotic graphical simulation package Open-System
Environment on a Silicon Graphics IRIST^© 4D / 80GT graphics workstation.
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Adaptive genetic algorithm for optimal printed circuit board assembly planning
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N. Wong, M.C. Leu (2)
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STC A, 42/1/1993, P.17
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Keywords: Assembly Machines, Algorithms, Optimization |
Abstract : We present a novel application of the genetic algorithm approach for
solving the problem of planning optimal placement-insertion sequence and
machine setup in printed circuit board (PCB) assembly The algorithm
starts with feasible solutions and utilizes genetic operators to
iteratively generate potentially better solutions in the optimization
process, similar to the biological evolution process. We first describe
the basic algorithm and its application to optimal planning for some
popular PCB assembly machines We then describe an adaptive genetic
algorithm, which has its rates of genetic operators changed
automatically during the iterative optimization process_ We use a
Wilcoxon signed rank test to show its performance improvement over the
fixed-rate genetic algorithm.
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CLIR - Clean room industrial robot for handling and assembly in semiconductor industry
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N. Roth (2), B. Schneider
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STC A, 42/1/1993, P.21
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Keywords: Robots, Assembly Lines, Clean Room, Contamination, Process Quality, Semiconductor mask, Pellicle |
Abstract : In many technical areas innovation is characterized by an increasingly
progressing miniaturisation leading to a situation, that a growing
spectrum of products has to be produced under clean room conditions.
Technical as well as economic reasons are responsible for the necessity
to automize large areas of that type of production, because even under
protective measures human workers produce an unacceptable amount of
pollution in clean rooms.
Industrial robots can be used in clean rooms, but they have to be
designed or at least to be largely modified to meet the requirements. In
this paper development and technical features of such robot systems are
described and results from an application in assembly tasks within
semiconductor production are discussed.
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Flexible solutions for wiring harness assembly with industrial robots
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H.J. Warnecke (1), H. Emmerich, S. Koller
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STC A, 42/1/1993, P.25
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Keywords: Automatic Assembly, Wiring, Flexibility |
Abstract : The wire harness assembly process has not changed fundamentally for many
years. All procedures except the pre-assembling of the individual wires
are done by hand. The labor-costs of wiring are very high in comparison
to the total costs of the assembly process.
A pilot work station for the fully automated direct-assembly of wires
into fluorescence lights has been developed. With the aid of a new
connection technology and the help of an industrial robot and special
tools the direct-assembly of individual wires into the light cases is
possible. First test results show that the procedure of the
direct-assembly works with a high availability and that this procedure
is more cost effective in comparison to the traditional wiring harness
assembly in many fields.
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STC C |
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Chip formation in the machining of hardened steel
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M.C. Shaw (1), A. Vyas
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STC C, 42/1/1993, P.29
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Keywords: Cutting, Cubic Boron Nitride (CBN), Chip Formation |
Abstract : With the availability of polycrystalline cubic boron nitride (PCBN) it
is possible to machine very hard gears, etc at speeds of (60-150 m / min
= 200-500 fpm). When this is done using PCBN tools in face milling, chip
formation is of a cyclic saw toothed type. This type of chip formation
is reviewed in relation to other types of cyclic and noncyclic chip
formation. The root cause of high frequency, saw toothed chip formation
is found to be periodic gross shear fracture extending from the free
surface of the chip toward the tool tip and not adiabatic shear as
commonly believed.
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Rigid-plastic FEM analysis of three-dimensional deformation fiels in chip formation process
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K. Ueda (2), K. Manabe
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STC C, 42/1/1993, P.35
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Keywords: Cutting, Finite Element Method, Chip Formation |
Abstract : A three-dimensional deformation field in the chip formation process is
analysed by the Rigid-Plastic Finite Element Method. By developing a
three-dimensional model of the work material, the deformation field in
oblique cutting is continuously analysed for the transition process from
the beginning of the cutting until the steady state. The variations in
the chip geometry and cutting forces due to the inclination angle of the
cutting edge are simulated for a carbon steel. The simulation results
are compared with in-situ scanning electron microscope observations of
the cutting experiments, and good correlation between them is found.
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Turning versus grinding - A comparison of surface integrity aspects and attainable accuracies
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V. König (1), A. Berktold, K.F. Kich
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STC C, 42/1/1993, P.39
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Keywords: Hard Machining, Surface Properties, Accuracy |
Abstract : In the past decade, the technology of machining hardened steels with
geometrically defined cutting edges has been developed. Despite its high
potential to increase productivity as well as competitiveness, the
industrial use is still low. That is because the effects of hard
machining on surface integrity aspects and the attainable accuracies
are not well understood. In this paper, the characteristics of hard
machined surfaces - especially of 'white layers' - will be discussed and
compared to those which are ground. Furthermore, the development in the
area of high precision machining of hardened steels will be presented.
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Automatic chip breaking detection in turning by frequency analysis of cutting force
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J.L. Andreasen, L. De Chiffre (2)
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STC C, 42/1/1993, P.45
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Keywords: Turning, Chip Control, Cutting Forces |
Abstract : An automatic system for chip breaking detection in turning has been
developed for use in the laboratory. The system utilises a detection
technique based on frequency analysis of the dynamic feed force
component. The ability to identify chip breaking has been demonstrated
using different lathes, cutting tools, workpiece materials and cutting data.
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Computer-aided predictive models for fundamental rotary tool cutting processes
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E.J.A. Armarego (1), V. Karri, A.J.R. Smith
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STC C, 42/1/1993, P.49
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Keywords: Cutting, Mechanics, Rotary Tools |
Abstract : Mechanics of cutting analyses fur fundamental `self-propelled' and
driven rotary tool cutting processes aired at coining an understanding
of the practical rotary tool turning and face milling operations are
presented. It is shown that these fundamental rotary tool processes can
be directly related to the `classical' orthogonal and oblique cutting
processes used to study the fundamentals cf conventional machining and
develop predictive yodels for the more complex practical -turning,
drilling and milling operations. Based on the unified mechanics of
cutting approach, computer-aided cutting models for predicting the force
components, power and chip flow angle in -he fundamental rotary tool
processes are discussed, experimentally verified and numerically
studied. The difficulties of extending these models to the practical
rotary tool operations are briefly discussed.
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Optimization of precision machining by simulation of the cutting process
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H. Schulz (1), K. Bimschas
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STC C, 42/1/1993, P.55
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Keywords: Precision Cutting, Simulation, Preventive Optimization |
Abstract : In order to produce high precision workpieces, sources of error are made
apparent through preventive simulation of the planned cutting process.
Machining optimization prior to the start of production is thereby made
possible, The simulation program developed by the Institute for
Production Engineering and Machine Tools (PTW) is based on a permanent
work-proceeding simultaneous transfer of force caused by the cutting
forces onto the present workpiece geometry. In order to improve the
precision of the workpiece the entire manufacturing system "machine tool
- workpiece - tool - clamping device - cutting technology - sequence of
operations" must be considered. The simulation of workpiece machining
and the optimization processes required to achieve higher precision will
be demonstrated. Utilization of this preventive simulation method can
gradualy reduce workpiece form failures.
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Estimation of cutting tool life by processing tool image data with neural network
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T. Teshima, T. Shibasaka, M. Takuma, A. Yamamoto / K. Iwata (1)
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STC C, 42/1/1993, P.59
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Keywords: Tool Life, Neural Networks, Image Processing |
Abstract : In the manufacturing Systems such as FMS, one of the most important
issues is to estimate the rest of cutting tool life under a given
cutting conditions as accurately as possible. In this paper, a system
based on neural network is proposed to estimate the life and wear type
of cutting tools from their image data and cutting conditions. The input
of the system is the states of a cutting tool, crater wear and flank
wear, obtained as image data, and the cutting conditions. The validity
of the system was confirmed by the examinations Under various cutting
conditions in turning.
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Reliability improvement of tool-wear monotoring
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A. Novak (1), H. Wiklund
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STC C, 42/1/1993, P.63
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Keywords: Process Monitoring, Tool Wear, Statistical Analysis |
Abstract : A method for on-line reliability evaluation of flank-wear measurements
and for immediate adjustment of improper data is presented in the paper.
Direct flank-wear measurements by a developed vision system and the
indirect sensing of tool condition by teed force measurements are two
simultaneously evaluated signals when two sources of possible
measurement errors are introduced and used for reliability estimates of
the acquired data.
Optimum settings of two parameters involved in the signal conditioning
strategy are calculated by applying response surface methodology (RSM)
and a suitable tool-wear model.
The described method has been applied to several machinability tests
performed during turning. A significant increase of monitoring adequacy
when compared with the traditional way of monitoring has been verified.
The accuracy and reliability of tool-wear monitoring by the developed
vision system, operating on the machine tool on-line, has been improved
as disclosed by the presented results.
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Unsupervised neural network for tool breakage detection in turning
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V.B. Jamu, K. Danai / S. Malkin (1)
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STC C, 42/1/1993, P.67
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Keywords: neural network |
Abstract : Ali unsupervised neural network is introduced for on-line tool breakage
detection in machining using multiple sensors. This neural network
performs detection by classifying the measurements either as normal or
abnormal. However, it performs classification by relying only on the
normal category, so that it does not need to establish the abnormal
category requiring samples of measurements taken at tool breakage. This/
Single Category-Based Classi//fier (SCBC) /also adapts the prototype
values on-line so as continuously update the normal category, and
employs the noise suppression technique: /contrast enhancement and
voting,/ in order to cope with different levels of noise in
measurements. The performance of the SCBC is evaluated in turning.
Extensive tests were performed which produced six tool breakage cases.
Four measurements which were clear indicators of tool breakage in these
tests were used as inputs to the SCBC and to two other classifiers
utilizing Kononen's Feature Mapping and Adaptive Resonance Theory
(ART2). The results indicate that the SGBC was the only classifier that
could detect all of the tool breakages.
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On multi-sensor approach to drill wear monitoring
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A. Noori-Khajavi, R. Komanduri (1)
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STC C, 42/1/1993, P.71
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Keywords: Drill Wear Monitoring, Sensors, Neural Network, Sensor Fusion |
Abstract : Single sensors were investigated in the past for their potential for
monitoring drill wear. Since, signals from different sensors may capture
wear differently at different stages of its life, sensor fusion concept
was advanced recently using multiple sensors. In this investigation,
this concept was explored in drilling using four sensors, namely,
thrust, torque, and strains in two orthogonal directions to the drill
axis (i.e., the X- and Y-directions on the table of a CNC milling
machine). The signals were analyzed in the time and frequency domains.
In the frequency domain, the Power Spectral Density (PSD) of sensor
signals showed good correlation with drill wear while in the time domain
no significant changes were observed between a sharp and a worn tool
Also, the signal-to-noise ratio analyses in the frequency domain at
different states of drill wear indicated that as the drill wear
increases the noise also increases. It was shown that when noisy sensor
signals were integrated (instead of using one sensor signal) using a
neural network, it may actually result in the deterioration of the
correct estimation of drill wear. Consequently, it appears that
integration of the sensor signals under these conditions may not be
appropriate and a single sensor may be adequate.
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Combined stress, material flow and heat analysis of orthogonal micromachining of copper
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T. Moriwaki (1), N. Sugimura, L. Sheng
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STC C, 42/1/1993, P.75
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Keywords: Cutting, Micromachining, Finite Element Method |
Abstract : Theoretical and experimental analyses of orthogonal micromachining of
copper are presented to promote fundamental understanding of
ultraprecision metal cutting process. A method is proposed by applying
the rigid-plastic FEM to analyze the mechanics of steady state
orthogonal micromachining process of copper taking into consideration of
the roundness of the tool edge. An FEM model is also developed to
analyze the flow of cutting heat and the temperature distribution within
both the workpiece and the .tool based on the stress and the material
flow within the workpiece calculated. Orthogonal micromachining
experiments are carved out by employing both a micromachining equipment
installed within SEM (Scanning Electron Microscope) and an
ultraprecision fly cutting machine. The results of the FEM analysis are
compared with the experimental results.
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Mechanics and energy dissipation in nanoscale cutting
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T. Inamura, N. Takezawa, Y. Kumaki / N. Ikawa (1)
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STC C, 42/1/1993, P.79
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Keywords: Simulation, Micromachining, Cutting |
Abstract : The methods by which to evaluate energy dissipation and stress/strain
distribution in nanoscale cutting have been presented and applied to the
results of atomic-model-based simulation of nanoscale cutting. The
results thus obtained show that the rate of energy dissipation in
plastic deformation under a tool is large compared with that in
macroscale cutting but that the value for surface generation is still
small. The results also show that the stress-and-strain distribution in
nanoscale cutting is consistent with that of macroscale cutting except
that there is almost no concentrated shear stress in the primary shear zone.
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Effect of tool edge geometry on energy dissipation in ultraprecision machining
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D.A. Lucca, Y.W. Seo / R. Komanduri (1)
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STC C, 42/1/1993, P.83
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Keywords: Cutting, Cutting Forces, Diamond |
Abstract : An experimental study of die effect of single crystal diamond tool edge
geometry on the resulting cutting and thrust forces and specific energy
in the ultraprecision orthogonal flycutting of Tc-Cu was made. The
effects of both the nominal rake angle and tool edge profile were
investigated over uncut chip thicknesses from 20 µm down to 10 nm.
Characterization of the tool edge was performed with the use of atomic
force microscopy. Both the nominal rake angle and tool edge profile were
found to have significant effects on the resulting forces and energies.
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Development of an advanced tool setting device for diamond turning
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M. Sawa, Y. Maeda, M. Masuda, R. Ito / T. Moriwaki (1)
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STC C, 42/1/1993, P.87
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Keywords: Aluminium Alloys, Diamond Tools, Diamond Turning Machines, Ultra-Precision Machining |
Abstract : This paper describes development of an advanced tool setting device for
diamond turning. In order to machine a magnetic recording disk substrate
(Al-Mg alloy) to a mirror-finished surface of less than 0.03 µm Rmax
using a diamond cutting tool, a mechanism has been developed for
automatic adjustment of the tool setting angle, which is a very
important factor to obtain a smooth machined surface. The adjustment of
the tool setting angle, which has previously been done by skilled
operators, is now automated and the angular tolerance subjected to the
tool replacement has been improved to an accuracy of ± 1.4 x 10^- 3
degrees. The machined surface roughness has also been improved to less
than 0.03 pm Rmax. Moreover, the time required for the tool setting
angle adjustment has been shortened to 5 minutes as compared to between
15 and 45 minutes required by the conventional manual adjustment.
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Feasibility study on ultimate accuracy in microcutting using molecular dynamics simulation
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S. Shimada, N. Ikawa (1), H. Tanaka, G. Ohmori, J. Uchikoshi, H. Yoshinaga
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STC C, 42/1/1993, P.91
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Keywords: Cutting, Micromachining, Computerized Simulation |
Abstract : Using molecular dynamics computer simulation, the feasibility is
analyzed on nanometric or an ultimate machining accuracy attainable in
microcutting of free machining workmaterials under perfect motion of a
machine tool; Based on the analysis, the microprocess of chip and
surface generation can be well understood from the atomistic point of
view. The minimum thickness cf cut, that is a measure of the accuracy
attainable, can he expected to be about 1 nm or less, that is, 1/20 to
1/10 of the edge radius of a realistic fine cutting edge available. The
ultimate roughness and depth of deformed layer of worksurface is
estimated to be about 0,5 nm and 5.0 nm, respectively. The quality of
worksurface of aluminum is worse thin that of copper These results
suggest that the ultraprecision metal cutting the machining accuracy of
which is at least 1 nm is feasible.
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A consideration of tool wear mechanism when machining metal matrix composites (MMC)
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K. Weinert / W. König (1)
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STC C, 42/1/1993, P.95
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Keywords: Composites, Machining, Tool Wear |
Abstract : The chip formation is very important for the comprehension of tool wear
mechanism when machining MMC. The real area of contact during the chip
formation is not well known. Therefore a clear determination of the type
of wear is only possible after a well-founded investigation on the wear
appearances.
These investigation have shown important differences if the hardness of
the reinforcement material is higher or lower than the hardness of the
cutting material. Furthermore the relation of the reinforcement particle
size and the grain size of the cutting material influences the wear
mechanism and the wear appearances.
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Performance of whisker-reinforced ceramic tools in milling nickel-based super alloy
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M.A. Elbestawi (2), Di Yang, Min Tan, T. Elwardany
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STC C, 42/1/1993, P.99
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Keywords: Cutting, Tool Wear, Ceramics |
Abstract : This paper investigates failure characteristics and cutting performance
of silicon carbide whisker-reinforced ceramic tools during milling of
Inconel 718. Cutting tests were performed using round and square
inserts, at cutting speeds ranging from 200 to 700 m/min, and feeds from
.05 to .15 mm/tooth. Various immersion ratios were also considered. Tool
wear was examined under the various cutting conditions. The behaviour of
the cutting forces and temperatures during machining were then examined.
The results show that an improved performance was obtained using the
round inserts in comparison with the square ones. Modes of tool failure
were found to be depth of cut notch wear and trailing edge wear. The
former wear was dominant at cutting speeds from 200 to 400 m/min while
the later wear was dominant at speeds from 400 to 700 m/min. Flank wear
was mainly due to adhesion of workpiece material on the tool surface.
The best performance was achieved at a speed of 700 m/min, feed of 0.15
mm/tooth and 1.25 mm depth of cut.
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High speed machining of inconel 718 with ceramic tools
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N. Barutaki, Y. Yamane, K. Hayashi, T. Kitagawa / K. Uehara (1)
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STC C, 42/1/1993, P.103
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Keywords: Nickel Alloys, High Speed Machining |
Abstract : High speed machining for Inconel 718 was carried out with SiC whisker
reinforced alumina, silicon nitride and TiC added alumina ceramic tools.
In this test, not only the commercial available inserts, square type
120408 or button type 120400, but also specially designed cutting edges
were tried. The SiC whisker tool showed the best performance in respect
of notch wear at the cutting speed of under 300m/min. However, when the
speed exceed 400m/min., the TiC added alumina ceramic tool showed the
smallest wear compare to other tools. Specially designed cutting edge
made the notch wear small.
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Ultra-precision machining of SiCw/Al composites
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Z.J. Yuan (1), L. Geng, S. Dong
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STC C, 42/1/1993, P.107
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Keywords: Composites, Cutting, Ultra-Precision machining |
Abstract : images/cirpfichiers/annals/SiCw/Al composite is a new material which has high strength and low
weight. In ultra-precision machining of the SiCw/Al composites with
single point diamond tool (SPDT), surface finish of Ra =0.0l ?m is
reached. In precision machining of the SiCw/Al composites, the
effections of percentage and direction of the SiC whisker and the
cutting parameters on cutting surface integrity of the SiCw/Al
composites are studied. The mechanism of cutting deformation of the
SiCw/Al composite is also searched with SEM and TEM analysis.
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Theoretical consideration of rare earth metal compounds as tool materials for titanium machining
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B. Kramer (2), D. Viens, S. Chin
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STC C, 42/1/1993, P.111
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Keywords: Tool Wear, Titanium Alloys |
Abstract : Previous work has suggested that tool materials that are effective in
the machining of titanium, such as tungsten carbide and diamond, promote
seizure between the tool and chip, producing a diffusion-limited, low
wear regime. Another strategy for decreasing tool wear is to identify
materials that have high chemical stability with respect to titanium.
Some rare earth metals are known to have relatively high enthalpies of
solution in titanium and their compounds are expected to have
corresponding low solubilities. Although much needed data concerning the
chemical and mechanical properties of rare earth compounds is
unavailable, the paper represents an attempt to evaluate the potential
of various rare earth metal compounds as tool materials for titanium
machining, on the basis of the limited available data.
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Proposition of a method to optimize the machining of XC42 steel with laser assistance
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J.F. Gratias, L.J. Fan, G. Marot, p. Cohen, A. Moisan (1)
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STC C, 42/1/1993, P.115
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Keywords: Laser Beam Cutting, Material Finishing, Optimization |
Abstract : This paper presents a method which permits to obtain relationships
between the main parameters to be considered during machining of steel
with laser assistance - the cutting speed, the laser beam power, the
melting temperature and the austenitic transformation temperature of the
machined material - in order to optimize the process. From a theoretical
approach and from experimental results obtained in turning with laser
assistance, laser power-cutting speed relations are established,
defining a zone in which the influence of the energy supplied by the
laser is most significant on the cutting force. Decreases of the cutting
force components up to 70%37; are observed, in proving the efficiency of
machining with laser assistance, principally in the case of
hard-strength materials.
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STC Dn |
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Development of machining-productibility evaluation method (MEM)
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S. Arimoto, T. Ohashi, M. Ikeda, S. Miyakawa / M. Kiuchi (1)
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STC Dn, 42/1/1993, P.119
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Keywords: Design, Productibility, Processability |
Abstract : The Machining-productivity Evaluation Method (MEM) was developed to
assess design quality for easier processing of parts and products. It
has been effectively used in the Hitachi Group and other companies. MEM
covers cutting (turning) and grinding, sheet metal working, welding,
molding, die casting, and casting. It features:
1) quantitative evaluation using easy to understand 100 points
evaluation scale and estimated processing cost index.
2) method is easy to both learn and use, using approximately 20
basic symbols
3) concurrent calculation of processing coast for workshop with
indices.
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A nex concept for design of sheet metal products
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M. Shpitalni (1)
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STC Dn, 42/1/1993, P.123
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Keywords: Design, CAD/CAM, Sheet Metal |
Abstract : An interactive CAD/CAM system dedicated to the design and manufacture of
sheet metal products has been developed. This paper discusses the unique
method used by the system for product definition. The product is defined
based on the principles of zero thickness and zero bend radii as well as
on manufacturing constraints. First, the product is defined in 2-D using
nominal dimensions. Then, transformation from the 2-D nominal layout to
the real 3-D product is performed by means of manufacturing constraints.
These constraints, including bending, welding, and critical dimensions,
introduce an important aspect of design for manufacturing.
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Design and application of a prototype system for concurrent engineering in a small firm
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W. Gijsels, W.R. De Vries (2)
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STC Dn, 42/1/1993, P.127
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Keywords: Concurrent Engineering, Process Planning, Data Base |
Abstract : Efforts to develop an integrated or concurrent engineering approach to
design and manufacturing often focus on large systems in large firms.
However smaller firms can also benefit from this approach. In this paper
we propose a database structure for handling the design of small
mechanical parts to be produced on a flexible manufacturing system. The
database the information on geometric models of part designs, models for
tools and fixtures manufacturing operations and detailed process plans
which are developed simultaneously. This prototype database structure
and planning system have been developed to run on an IBM PS/2 or
equivalent. This paper outlines the data structure design and the
planning assumptions that are made to implement such system. The system
is illustrated by applying it to realistic part designs.
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Systematization of design knowledge
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H. Yoshikawa (1)
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STC Dn, 42/1/1993, P.131
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Keywords: Design, Computer Aided Design, Knowledge Based System |
Abstract : It is expected that future design/manufacturing systems should be
autonomous, metamorphological, self-organizing,
self-maintaining/recovering, and intelligent. To develop such systems,
the concept of knowledge intensiveness plays a crucial role. Developing
knowledge intensive systems requires building large scale knowledge
bases on manufacturing and design. Our experiences with developing a
large scale design knowledge base for intelligent CAD systems show,
however, that without systematizing design knowledge it is impossible
even just to collect knowledge. This paper discusses aims, goals, and
roles of design knowledge systematization and proposes a systematization
methodology. Some preliminary results are also described.
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A generic mechanism model for use in a CIM environment for the development of mechanized production machines
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W. Zhang, K. Van Der Werff / C.A. Van Luttervel (1)
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STC Dn, 42/1/1993, P.135
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|
Keywords: Mechanism, Model, Database |
Abstract : In production machines mechanisms are important components. Such
mechanisms have to be designed taking into account many different
aspects. Communication with many other specialists may be required. A
project called "computer integrated manufacture of mechanism (CIMOM)"
was started at TU Delft. The goal of this project is to develop a
computer-based information system to support all activities necessary
for the integrated and automated design and manufacture of mechanisms. A
generic model for mechanisms plays an essential role in the CIMOM
environment. This paper focuses on the formulation of this mechanism
model. Database technology is used. The conceptual schema of the
mechanism model is presented. Some prototype implementations are
reported to prove the effectiveness of this model.
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Customerbased design with constraint reasoning
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G. Sivard, L. Lindberg, E. Agerman (2)
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STC Dn, 42/1/1993, P.139
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|
Keywords: Interactive Design Systems, Automated Design, Constraint Logic Programming |
Abstract : This paper identifies some principles for computer-aided customer-based
design. In this type of design, technical prerequisites and the range of
customer requirements are typically the same over time. From time to
time there are larger changes in manufacturing methods and customer
needs, though. Thus the degree of automation to a design support system
can be fairly large, but it still needs to be interactive and flexible
for changes. A test-case based on an industrial application, implemented
using a commercial CAD system and a CLP (Constraint Logic Programming)
system, is described. Special emphasis is put on interactivity- the
collaboration between designer and automated design system.
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|
A CAD for functional design
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|
T. Tomiyama, Y. Umeda / H. Yoshikawa (1)
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STC Dn, 42/1/1993, P.143
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|
Keywords: Design, Conceptual Model, Function |
Abstract : Although functional design (or conceptual design) is crucial to whole
design process, traditional CAD technology based on geometric modeling
does not support this process because of difficulty of dealing with
function. This paper proposes a new methodology to deal with function,
called FBS (Function-Behavior-State) modeling and describes a computer
tool support functional design based on the FBS modeling. Importance and
advantages of the FBS modeling is clarified by demonstrating two
examples. One is the design of functionally redundant machines and the
other is the automatic generation of control software for mechatronics
products.
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|
Product and process modelling as a kernel for virtual manufacturing environment
|
|
F. Kimura (2)
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STC Dn, 42/1/1993, P.147
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|
Keywords: Product Engineering, Computer Models, Computer Integrated Manufacturing |
Abstract : For coping with severe requirements for future manufacturing systems, it
is effective to model necessary product behaviour and associated
manufacturing processes by computer as precisely as possible, and to
predict potential problems for product functionality and
manufacturability before making real manufacturing. This approach is
called as virtual manufacturing. In this paper, a set of models
pertinent for realizing virtual manufacturing environment is introduced.
Among them product and process modes are discussed in some details as a
kernel. Product models represent every artifact which appears during
manufacturing, and process models are associated with them to derive
their properties and behaviour. Some examples are given to show the
effectiveness of virtual manufacturing.
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|
Methods for quality driven product development
|
|
F. L. Krause (2), A. Ulbrich, R. Woll
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STC Dn, 42/1/1993, P.151
|
|
Keywords: Design, Quality Assurance, Product Development |
Abstract : This paper introduces approaches for the integration of the QFD and FMEA
methods as well as feedback with system components for computer aided
product development. The integration is based on information models
representing product, process and factory information. These information
models will be extended by requirements and failure models to support
the above mentioned quality assurance methods. A quality information
model for company-wide information delivery is defined and forms the
control of the quality driven product development process by integration
of a system component for quality control.
|
|
Process driven engineering - A key element in integrating design and manufacture
|
|
A. Geddam, S. Kaldor (2)
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|
STC Dn, 42/1/1993, P.155
|
|
Keywords: Process Driven Design, Design For Manufacture, Precision Machining |
Abstract : Traditionally, design and development activity has been and still is
completely separated in many places from engineering and from
production. This has often led to dead ends when production could not
keep up with requirements due to lack of suitable processes. Further, in
the past, this could not happen since it was natural to develop and
build prototypes in the manufacturing environment and through help from
manufacturing personnel. Modern trends like concurrent engineering
emphasize free information flow between production engineering and
design, aimed at an integrated approach to design and manufacture. This
paper deals with design and engineering methods which are based on
available and specific processes. Examples from the fields of inertial
devices and thermal imaging are discussed.
|
|
Notes on concurrent engineering
|
|
L. Lindberg / G. Sohlenius (1)
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|
STC Dn, 42/1/1993, P.159
|
|
Keywords: Concurrent Engineering, Design, System Theory |
Abstract : This paper discusses Concurrent Engineering from a system perspective.
The approach is to use analogies to control systems to illustrate
central problems in Concurrent Engineering. 'Notation' is then presented
as a useful concept to discuss the representation of the data flowing in
the manufacturing system. This also shows that to perform a quantitative
analysis a formal definition of information is needed, with an
associates measure of it.
|
|
The life cycle concept as a basis or sustainable industrial production
|
|
L. Alting (1), J. Jorgensen
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|
STC Dn, 42/1/1993, P.163
|
|
Keywords: Product Development, Design, Life Cycle, Environment |
Abstract : The Life cycle concept will become the backbone in a new industrial
culture named sustainable production. Sustainability means that products
are designed for their whole life cycle i.e. production, distribution,
usage and disposal with minimized (acceptable) influence on the
environment, occupational health and use of resources. A key element in
this new engineering life cycle approach is a method/ tool to assess and
evaluate environmental. occupational health and resource consequences in
all life cycle phases at the product development stage. In this paper a
preliminary method for evaluating environmental consequences containing
the major environmental effects is presented. The method outlined
quantifies the term "environmental friendly" so it can be used as a
"yardstick" in evaluating different technical solutions. The complex
problems in the final design decisions are discussed and future
perspectives outlined.
|
|
Evolving issues in product life cycle design
|
|
V.A. Tipnis (2)
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|
STC Dn, 42/1/1993, P.169
|
|
Keywords: Product Design, Process Design, Environmental Impact, Competitive Strategies, Concurrent Engineering, Economic Model, Penalty Costs |
Abstract : Driven by the global environmental movement and consumer preferences to
`green labeled products', a new paradigm has emerged:{`GREEN' ROBUST
PRODUCTS} plus {CLEAN PRODUCTION) equals (SUSTAINABLE GROWTH}.This
paradigm evolved from the growing environmental regulations and
occupational health and safety laws that restrict gaseous, liquid, and
solid emissions and waste disposals from manufacturing processes and
products in-use and -disposal. Also, disposal of product packaging and
recycling of used products is forcing the rethinking of the entire
product life cycle from product strategy to recycling/disposal. There is
a growing recognition of the fact that the competitive position and,
indeed, the very, survival of companies depend on their response to this
paradigm. This new paradigm is named the paradigm 'E' because to adopt
it, a corporation must emphasize Ecology, Environment, Energy, Economy,
Empowering, Education, and Excellence in all product fife cycle
decision. Responding to this paradigm poses several new challenges
beyond the traditional role and expertise of most product designers and
production engineers. In this paper, the evolving issues of the paradigm
and their impact on product design and production are examined. The
steps necessary for the adoption of die paradigm 'E' are presented. A
review is presented of the available methodologies and analysis tools
for making evaluation of environmental impact, product life cycle
economics, and corporate competitive positioning. Activity modeling
which provides a comprehensive methodology for these investigations is
illustrated through sample outputs from an on-going industrial
implementation of the Paradigm 'E'.
|
|
Information-based design for environmental problem solving
|
|
D.R. Wallace, N.P. Suh (1)
|
|
STC Dn, 42/1/1993, P.175
|
|
Keywords: Design, Axioms, Design Requirements |
Abstract : Axiomatic design is a general method that helps designers structure and
understand design problems, thereby facilitating the synthesis of
suitable design requirements, solutions, and processes. The approach
also provides a consistent framework from which the merits of designs
can be quantified. In this paper we briefly review the tenets of
axiomatic design, and demonstrate how information content can he applied
to environmental design problems - an issue that is becoming
increasingly important. A prototypical computer program is used to
illustrate the approach.
|
|
Life-cycle-analysis : a strategic element for future products and manufacturing technologies
|
|
H. Weule (1)
|
|
STC Dn, 42/1/1993, P.181
|
|
Keywords: Ecology, Life-Cycle-Analysis, Design Requirements |
Abstract : Environmentally clean products and manufacturing technologies are vital
in order to be competitive in the future. Beside functional requirements
product design must be more and more oriented on ecological effects
throughout the life-cycle of products. Life-cycle-analysis permits the
comparison and evaluation of various alternatives from the ecological
and economical point of view. The method for life-cycle-analysis is
illustrated. For two alternative suction tubes for a vacuum cleaner the
first approach for an "ecobalance" is outlined.
|
|
3D shape reconstruction for recognition of freehand machine drawings
|
|
T. Honda (2), S.I. Kaneko, Y. Takeda
|
|
STC Dn, 42/1/1993, P.185
|
|
Keywords: Drawing, Design, Vision |
Abstract : An algorithm to reconstruct three dimensional geometries of machine
parts based on the two dimensional data generated from two orthographic
projection views of machine drawings has been developed, and implemented
to a system for recognition of freehand written machine drawings that
has been under research and development by the authors since 1984.
For machine parts with geometrical elements of planes, cylindrical
surfaces and holes, the system can generate the overall 3D shapes from
the two orthographic projection views data under some restrictions. In
this paper, the algorithm is shown with some test results. Furthermore,
the evaluation of the computing time is discussed comparing the
theoretical estimation with the actual measurement.
|
|
Performance rating of spur gears with non-standard proportions and profiles
|
|
M.A.S. Arikan (2), O.Uyar Carkoglu
|
|
STC Dn, 42/1/1993, P.189
|
|
Keywords: Gears, Gear Cutting |
Abstract : Although it is common practice to design gears with standard proportions
and cut them by using standard cutters and machines, considerable
performance improvements can be obtained either by designing and cutting
gears with non-standard proportions, i.e. gears with addendum
modifications: or by relieving their tips and/or roots. In this study,
effects of designing and cutting with non-standard proportions, and
giving tip and/or root reliefs on performance of spur gears are
investigated by using gear tooth models formed by using the geometry of
the canter. Variations of dynamic loads on spur gears during a mesh
cycle of a tooth, is found by using an analytical model based on
torsional vibrations of gears. Finite element method is used to find the
variable stiffness of gear tooth and to make the stress analysis.
Bending deformations of gear bodies and supporting shafts, bearing
deformations, torsional deformations of gear bodies, and contact
deformations of teeth are also included in stiffness calculations.
|
|
Skeleton-based design analysis of near net shape products
|
|
C.N. Chu, J.M. Lee (2), R.L. Kashyap
|
|
STC Dn, 42/1/1993, P.193
|
|
Keywords: Design, Near Net Shapes, Productability |
Abstract : In this paper, we present a parallel thinning algorithm for design
analysis of near net shape products. The parallel thinning algorithm
allows extraction of global topology of a three dimensional geometry. In
this scheme, the geometry is digitized and a skeleton line of the
geometry is extracted by preserving the Euler characteristics and
connectivity. The extracted skeleton allows a design evaluation system
to utilize heuristic manufacturing knowledge base. Finally, we construct
a skeleton model and present its application to casting and forcing
design analysis.
|
STC E |
|
Progress toward clean technology for photochemical machining
|
|
D.M. Allen (2)
|
|
STC E, 42/1/1993, P.197
|
|
Keywords: Environmental Impact, Etching, Waste Treatment |
Abstract : In order to compete with traditional mechanical methods of manufacture,
photochemical machining has undergone many process modifications in
order to comply with a plethora of legislation and regulations aimed at
protecting the environment. These modifications have greatly reduced the
environmental impact of the process and the drive to reduce it further
continues. This paper describes the cleaner photographic, metal
preparation, coating and etching technologies that have been developed
and includes details of current research directed towards economic
recycling of spent etchants.
|
|
A finite element simulation of the electrochemical machining process
|
|
H. Hardisty, A.E. Mileham, H. Shirvani / A.N. Bramley (1)
|
|
STC E, 42/1/1993, P.201
|
|
Keywords: Electrochemical Machining, Finite Elements, Simulation |
Abstract : The paper describes package based on the FEM (Finite Element Method),
which simulates the Electrochemical Machining (ECM) process. The FEM is
used to determine the two-dimensional potential and flux distribution in
the electrolyte, in order to estimate surface erosion for a finite
time-step. Algorithms have been developed which automatically change the
F.E. mesh, to simulate moving boundaries for tool movement and workpiece
erosion. The complex flux distributions produced in the electrolyte have
yielded considerable insight into the erosion process for the tool
shapes used unpractice.
|
|
Depth prediction in laser machining with the aid of surface temperature measurements
|
|
G. Chryssolouris (1), A. Yablon
|
|
STC E, 42/1/1993, P.205
|
|
Keywords: Laser Machining |
Abstract : This paper discusses a method for estimating the groove depth in laser
machining processes based on temperature measurements. The temperature
field was measured through infrared thermography. An analytical model
relating temperature to groove depth was used to predict the groove
depth given a temperature measurement and its location. Theoretical and
experimental results are compared and discussed.
|
|
Dynamic stability of the technological machining system in EDM
|
|
S. Enache (1), C. Opran
|
|
STC E, 42/1/1993, P.209
|
|
Keywords: EDM, Technological Oscillations, Dynamic Stability |
Abstract : The paper presents the results of the theoretical and experimental
research concerning the physical model, the transfer functions and the
equations of the dynamic stability on processing in EDM. It also deals
with the influence of the electro-technological factors upon the
technological oscillations, characteristic of the tool-electrode of the
EDM.There is also shown the influence exerted by these technological
oscillations on the productivity, roughness of the machined surface and
manufacturing precision. This is a continuation of the paper introduced
at CIRP 1990.
|
|
Thin plate welding by a high-power-density small diameter plasma arc
|
|
S. Yoshioka, T. Miyazaki, T. Kimura, A. Komatsu, N. Kinoshita (1)
|
|
STC E, 42/1/1993, P.215
|
|
Keywords: Plasma Arc Welding, Tolerances, Control |
Abstract : High-power-density plasma arc of 10^4 W/mm² (10^6 W/cm²) is applied to
welding of stainless steel plate of 0.1 and 0.3 mm in thickness.
Practical conditions required for successful welding and welding
capability of this new equipment are discussed. Welding capability does
not depend on the working distance defined as the distance between exit
of nozzle and workpiece surface. Furthermore, even though the plasma
torch is deviated from the right position, appropriate welding can be
successfully carried out because the workpiece is the anode in this
process and thus all power is supplied to the workpiece.
|
|
Metal surface modification by electrical discharge machining with composite electrode
|
|
N. Mohri, N. Saito, Y. Tsunekawa / N. Kinoshita (1)
|
|
STC E, 42/1/1993, P.219
|
|
Keywords: Electrical Discharge Machining, Surface Properties, Composites |
Abstract : This paper presents a new method of surface modification by electrical
discharge machining using composite structured electrode. Surface
modifications on work pieces of carbon steel or aluminum were carried
out in hydrocarbon oil using composite electrodes. Composite electrode
consists of' green compact products or sintered products. Copper,
aluminum, tungsten carbide and titanium were used for the material of
the electrode. It was revealed that there existed the electrode material
in the work surface layer and the characteristics of' the surface of raw
material remarkably changed. These surfaces have less cracks, higher
corrosion resistance and wear resistance.
|
|
On the maximum depth and profile of cut in pulsed Nd : YAG laser machining
|
|
C.Y. Jiang, W.S. Lau (1), T.M. Yue
|
|
STC E, 42/1/1993, P.223
|
|
Keywords: Laser Beam Machining, Depth, Dimension |
Abstract : The maximum depth in pulsed Nd: YAG Laser machining is one of the
critical problems due to the relatively small mean beam power. A
theoretical model is established to predict the depth of machining by
considering the laser beam intensity distribution and file interaction
of the beam with the material. The influence of the focal spot position
on the depth of machining is analyzed and experimentally investigated.
Moreover, the transverse sectional shape of the machined hole or slot
can also be approximately predicted.
|
|
Environmentally friendly and high capacity dielectric regeneration for wire EDM
|
|
G.N. Levy (1)
|
|
STC E, 42/1/1993, P.227
|
|
Keywords: Wire EDM, Filters, Environmental Impact |
Abstract : In wire EDM the most frequently used dielectric is water. During recent
years a significant progress in cutting speed has been achieved. This
requires an efficient and long term autonomy regeneration system. On the
other hand, the environmental impact on machining has become more
relevant. Use of water bears some risks. A filtration unit based on
membrane technology which fulfills both requirements is described, and
experimental results are presented and discussed.
|
|
Study of pulse electrochemical machining characteristics
|
|
K.P. Rajurkar, J. Kozak, B. Wei / J.A. McGeough (1)
|
|
STC E, 42/1/1993, P.231
|
|
Keywords: Electrochemical Machining, Modelling, Acuracy |
Abstract : The Pulse Electrochemical Machining (PECM) promises to improve
dimensional accuracy control and to simplify tool design in machining
hard, high strength, and heat resistant materials into complex shapes
such as turbine blades. This paper presents a mathematical model for the
PECM process which takes the non-steady physical phenomena in the gap
into consideration, A specially-built PECM cell and a high-speed data
acquisition device are used to obtain accurate experimental results for
the model verification. The interelectrode gap characteristics,
including pulse current, metal removal rate, effective volumetric
electrochemical equivalent and electrolyte conductivity variations, are
analyzed based on the model and experiments.
|
|
Droplet-based manufacturing
|
|
J.H. Chun, C.H. Passow / N.P. Suh (1)
|
|
STC E, 42/1/1993, P.235
|
|
Keywords: Deposition, Liquids, Processing |
Abstract : Droplet-based manufacturing (DBM) processes are promising production
techniques for metallic parts and coatings with unique properties. In
DBM processes, molten metal droplets are produced and deposited onto a
substrate where they solidify to form near-net-shape parts. The quality
of parts formed using such processes depends on the precise control of
droplet size, flux, velocity and temperature. This paper presents an
experimental study on the effect of droplet impact states and mass flux
of the spray on deposit characteristics, using a unique DBM apparatus
that generates molten metal droplet sprays with precisely controlled
droplet size, mass flux and thermal state.
|
|
Ion beam fabrication of ultra-fine patterns on cemented carbide chips with ultra-fine grains
|
|
I. Miyamoto, N. Taniguchi (1)
|
|
STC E, 42/1/1993, P.239
|
|
Keywords: Dies, Cemented Carbide, Ion Beam Machining, Patterns, Electron Beam, Masks |
Abstract : This paper describes the fabrication of opto-electrical and
opto-mechanical devices by transferring ultra-fine patterns on cemented
carbide dies into a glass substrate. Photo resist masks made by electron
beam lithography were transferred into cemented carbide chips with grain
sizes of 2-3 pm and 0.5 um using a Kaufman type ion beam machining
apparatus. The cemented carbide chip, with ultra-fine grain of 0.5 um,
machined with 1.0 keV argon ions, has fine surface under 4-5 nm in Ra
and 12-20 nm in Rz, and the chips may be useful as the substrate for
dies. The transferred dies have good pattern profile and photo resist
masks also have fairly good etch selectivity for etching by ion beam.
|
|
Controlling of Q-switched YAG laser beam machining by generated sound
|
|
T. Miyazaki, Y. Tanaka, T. Tokunaga / N. Taniguchi (1)
|
|
STC E, 42/1/1993, P.243
|
|
Keywords: Acoustic Detectors, Control, Laser Beam Machining |
Abstract : Q-switched YAG laser beam machining processes are monitored by sensing
generated sound. The generated sound pressure varies with the focusing
condition of the laser beam, kind of the workpiece material and removal
rate. A system for improving the machining capability is newly
developed, which can perform the Laser oscillation switching, automatic
focusing and refocusing of the beam. In the system, drilling operation
can be automatically started and finished. A hole can be drilled to the
rear surface of 2 mm thick Si_3 N_4 , plate in 8 s; this plate cannot be
drilled through to the near surface without this system.
|
|
Micromachining using excimer lasers
|
|
H.K. Tönshoff (1), D. Hesse, J. Mommsen
|
|
STC E, 42/1/1993, P.247
|
|
Keywords: Excimer Lasers, Micromachining, Micromechanical Parts |
Abstract : Excimer lasers can be used to machine metals, ceramics and polymers, UV
radiation with short pulses of several 10 ns and intensities much higher
than those of other sources allow machining with minimum thermal
influence. The high photon energy of excimer laser radiation facilitates
a direct photolytic interaction with the material. Besides this thermal
and pyrolytic interaction mechanisms also appear. Considering on this,
the removal mechanisms of certain materials are discussed. The
application of special features of this micro-machining center are the
beam handling system with integrated flexible mask and energy control.
The workpiece handling and all process parameters are controlled by a
host computer with ergonomic user interface.
The unit can be used to generate microstructures in ceramic and polymer
surfaces. Furthermore, it is possible to produce micro-mechanical parts
of these materials, also in fibre reinforced plastics.
|
|
Anode erosion in wire-EDM. A theoretical model
|
|
G. Spur (1), J. Schönbeck
|
|
STC E, 42/1/1993, P.253
|
|
Keywords: Process Models, Wire-EDM, Finite Element Method |
Abstract : Theoretical predictions concerning the machinability of different
materials by EDM are difficult because numerous aspects govern this
problem. The influence of the thermo-physical material properties which
play a dominant role can be studied best b_y a theoretical model Thus. a
new model which s tailored after a typical wire-EDM discharge has been
developed and experimentally verified. The model describes the impact of
a discharge on the anode as a heat source on a semi-infinite solid
whose size and intensity are time-dependent. The numerical analysis of
this mathematical problem has been performed by using the Finite
element method.
|
|
Three dimensional printing : the physics and implication of additive manufacturing
|
|
E. Sachs (2), M. Cima, J. Cornie, D. Brancazio, J. Bredt, A. Curodeau, T. Fan, S. Khanuja, A. Lauder
|
|
STC E, 42/1/1993, P.257
|
|
Keywords: Castings, Ceramics, Computer Aided Design (CAD), Metals and Alloys, Toolmaking |
Abstract : Three Dimensional Printing is a process for creating parts directly from
a computer model. 3D Printing builds parts in layers by spreading a
layer of powder and then selectively joining the powder in the layer by
ink-jet printing of a hinder material. After all layers are printed, the
loose powder is removed to reveal the finished pan. Application areas
include ceramic molds for metal castings, directly printed parts for
end-use and for use as tooling, ceramic preforms for metal matrix
composites, structural ceramic parts and others.
3D Printing is a member of a group of layer manufacturing techniques
which have the primary distinguishing feature of creating parts by the
controlled addition (rather than subtraction) of material. The primitive
building element in 3D Printing is a spherical ensemble of powder
particles held together by one droplet of binder. Ballistic effects are
important in the formation of primitives due to kinetic energy
associated with the incoming droplet_ Stitching together of droplets
forms surfaces and hence determines surface finish. Vertical dimensional
control is determined in part by the compression of powder layers by
subsequently applied powder. These physical mechanisms help to determine
the dimensional control and surface finish of 3D Printed parts.
|
STC F |
|
Computer aided simulation of extrusion and/or drawing of fin-tubes and fin-bars
|
|
M. Kiuchi (1), S.I. Jima
|
|
STC F, 42/1/1993, P.261
|
|
Keywords: Fin-Tube, Fin-Bar, Extrusion, Drawing, Simulation |
Abstract : An analytical method based on the upper hound method has been developed
for investigating into deformation features of workpieces in dies for
extrusion and/or drawing of fin-tubes and fin-bars which have
longitudinally straight radial-fins on their outside or inside surfaces.
The general equations which denote velocity fields of workpieces in dies
are formulated and the mathematical procedure for overall analysis is
established. By this method, power requirement, extrusion pressure,
drawing stress, precise geometry of extruded or drawn fin-tube and
fin-bar and geometry of die desirable for making fins as high as
possible are successfully calculated and predicted. Through a series of
analyses, effects of working conditions on shapes and dimensions of
manufactured fin-tubes and fin-bars have been consistently clarified.
Moreover, knowledges helpful for design of dies and processes have been
systematically obtained.
|
|
Computer-aided modeling of a new copper extrusion process
|
|
T. Reinikainen, A.S. Korhonen (1), K. Andersson, S. Kivivuori
|
|
STC F, 42/1/1993, P.265
|
|
Keywords: Forming, Extrusion, Finite Element Method |
Abstract : The general principles in the development of forming processes and
processes for the production of semi-finished copper products in
particular are briefly discussed. Conform extrusion is chosen as an
example of a novel copper extrusion process. Finite modelling of the
Conform extrusion is carried out after making simplifying assumptions on
the deformation geometry. The distribution of strain, strain rate and
temperature is studied by making FEM calculations on a workstation computer.
|
|
Central bursting defects in drawing and extrusion numerical and ultra-sonic evaluation
|
|
N. Alberti (1), A. Barcellona, A. Masnata, F. Micari (2)
|
|
STC F, 42/1/1993, P.269
|
|
Keywords: Drawing, Numerical Models, Ultrasonic Control |
Abstract : A new approach for the prediction of central bursting defects in
extrusion and drawing is proposed: a finite element analysis of the
processes has been carried out, and the obtained results have been
elaborated by means of a post-processor, which, employing a proper
ductile fracture criterion, is able to suggest if and where the central
burst occur. An ultrasonic control system able to detect the insurgence
of defects with a resolution of 0.2 mm. has been setup in order to
verify the predictive capability of the model. The experimental results
show a good agreement with the numerical predictions confirming the
effectiveness of the proposed approach, whose industrial application
appears very suitable.
|
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Analysis for the automation of small batch manufacturing using open die forging
|
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B. Aksakal, F.H. Osman, A.N. Bramley (1)
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STC F, 42/1/1993, P.273
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Keywords: Open Die Forging, Upper Bound, Automation |
Abstract : Open die forging is a long established process which can be used to
produce a wide range of shapes. Its characteristics features in
relationship to other types of forging processes are hat it requires low
forming loads and only a small range of simple tools to make a wide
variety of shapes. Whilst the process is generally associated with the
production of large forgings, an automated version could be attractive
for small batch manufacturing of low weight forgings. Such a system
could compete effectively against machining process. This paper examines
the process of pressing small size parts by open die forging, reviews
existing literature and presents an upper bound based solution for
single step and incremental open die forging. The validity of the
theoretical analysis is assessed by comparison with experiments and
found to be in a good agreement.
|
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Tool cost estimating at the early stages of cold forging process design
|
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P.F. Bariani (2), G. Berti, L. D'Angelo
|
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STC F, 42/1/1993, P.279
|
|
Keywords: Tool, Cost Estimating, Cold Forging |
Abstract : Identifying the most appropriate sequence of cold forging operations for
a new part requires a number of technological and economical evaluations
concerning loads, mechanical properties of the forged component, its
producibility on the machines as well as costs for equipment and
associate tooling.
This paper presents a methodology for estimating initial and maintenance
costs for cold forging tools. This methodology is for use of planners at
the early stages of process design, when the sequence of forging
operations and equipment are decided and before details of the tooling
system are available.
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Optimization of cold rolling of precision tubes
|
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P. Hulm (2), R. Fogelholm, A. Salwen
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STC F, 42/1/1993, P.283
|
|
Keywords: Forming, Cold Rolling, Tubes, Simulation |
Abstract : The goal for the optimization of process and material parameters in cold
rolling of precisions tubes is a product with accurate dimensions,
without eccentricities, possessing eligible final properties. The common
practice of such optimization is based on experience and empirical
know-how. In this paper is described a systematic approach based on a
computer assisted process model combined with an appropriate
characterization of the material behaviour in this process. The
developed models allow to cut down experimental investigations and
trials otherwise necessary for a proper choice of a optimal combination
of the process and material parameters.
|
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Design, analysis and experimental verification of the pack rolling process
|
|
J.S. Gunasekera (2), A.F. Ali, R. Anbajagane
|
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STC F, 42/1/1993, P.287
|
|
Keywords: Rolling, Forming, Design, Finite Element Method |
Abstract : The paper presents a design and analysis approach for the pack rolling
process to determine the stability in terms of the correct dimensions of
the material and the desired microstructure without defects. Pack
rolling involves the rolling of "difficult-to-form" materials within a
pack or cover material. Simulation of the process require, modeling, the
physics of the pack rolling process; the temperature distribution, the
velocity discontinuities between the cover plate and the workpiece, and
the deformation process. An analytical model was developed for
simulating the pack rolling process which utilizes a cinematically
admissible velocity field to determine tine relative slip between the
cover plate and the workpiece, a heat transfer module determines the
temperature distribution, and the deformation analysis is modeled by a
modified slab method. A 3D finite element analysis with coupled heat
transfer for pack rolling is presented. The pack rolling model was
correlated with experiments and the more accurate finite element model.
|
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Determination of optimum forming path in three-roll bending by combination of fuzzy reasoning and finite element simulation
|
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K. Osakada (1), G. Yang, K. Mori
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STC F, 42/1/1993, P.291
|
|
Keywords: Roll Bending, Tools, Flexibility, Finite Element Method, Sheet Metal |
Abstract : A method for determining the optimum forming paths in the roll-bending
process of plates by combining the finite element simulation with the
fuzzy reasoning is proposed. In this method, the forming conditions in
the finite element simulation are automatically changed to attain the
desired shape of the plate with the help of the fuzzy reasoning by
monitoring the calculated results such as the curvature of the plate,
the stress and strain distributions, etc. in each deformation step. To
form the front and the rear ends of a plate into a proper curvature by
three-roll bending, it is essential to give an appropriate path of the
top roll. For this purpose, the optimum motion of the top roll is
successively searched for in the finite element simulation. The fuzzy
reasoning is used to determine the motion of the top roll by taking
account of the effects of the plate thickness, the flow stress and the
difference between the desired and the calculated curvatures. It is
shown that the decrease in the curvature near both ends of the bent
plate is prevented by the use of the present method.
|
|
Roll bending of thin sheet metal parts on press brakes
|
|
E. Von Finckenstein , F. Haase, M. Kleiner, G. Reil, R. Schilling, H. Sulaiman
|
|
STC F, 42/1/1993, P.295
|
|
Keywords: Roll Bending, Tools, Flexibility, Finite-Element-Method, Sheet Metal |
Abstract : Increasing the flexibility of the sheet metal forming technology is the
aim of various research projects. A special tool system for roll bending
thin sheet metal parts on conventional press brakes is presented in this
article. Furthermore a finite element simulation (FEM) provides more
information which is necessary for an additional optimizing of this tool.
|
|
The mechanism of laser forming
|
|
M. Geiger (2), F. Vollertsen
|
|
STC F, 42/1/1993, P.301
|
|
Keywords: Forming, Laser Beam Application, Simulation |
Abstract : Laser forming is a complex dynamic forming process. Its basic feature is
the forming by thermal stresses, induced by irradiation of a laser beam.
A two-layer model for laser bending is proposed, which is capable to
describe the process in spite of many restrictions which have to be
made. It is shown that the coefficient of thermal expansion is one of
the most significant parameters for the process. The model shows the
right dependence on the sheet thickness and the right order of magnitude
for the bend angle which can be obtained in one step of the laser
bending process. Possible extensions of the model are discussed, using
experimental results which had shown that the neutral line lies at a
relative thickness z/s_0 =0.65.
|
|
Modelling and simulation of the aquadraw deep drawing process
|
|
J.C. Gelin (1), P. Delassus
|
|
STC F, 42/1/1993, P.305
|
|
Keywords: Aquadraw Process, Finite Element Method, Flow Control |
Abstract : The aquadraw deep drawing operation with an hydraulic counter-pressure
where the die cavity is filled of an hydraulic fluid is analyzed taking
into account as well as hydraulic flow between the die and the sheet
metal as deformation of the sheet material. The analysis developed in
the paper focuses on the main parameters that controls the process. An
hydraulic study of the pressure in the die cavity and an analysis of the
flow between the die cavity and the sheet metal are presented and
qualitative results are given that agree experimental ones. The
deformation of the sheet metal is analyzed using a finite element
approach taking into account the fluid pressure distribution. The
results of the numerical simulations in the case of axissymmetric parts
are compared with experimental ones obtained on an instrumented aquadraw
press and the agreement is good. The results obtained can be used for a
better control of the die cavity pressure to optimize the thickness
strain in the formed shape for the given process parameters.
|
|
Determination of the remaining formability in formed sheet metal parts from grid measurements carried out by computer image processing technique
|
|
J. Danckert (2), K. Albrektsen
|
|
STC F, 42/1/1993, P.309
|
|
Keywords: Forming, Sheet Metal, Strains |
Abstract : The paper presents a computer based system for 1) The measurement of a
grid applied to the surface of the sheet metal part, 2) Analysing the
strain distribution and 3) Determination of the remaining formability in
the finished sheet metal part taking history into account.
A grid is applied to the surface of the undeformed blank. After forming
the grid is measured by computer image processing technique. The strains
are calculated automatically and can be displayed on the computer screen
in various ways e g. as a process signature together with the forming
limit curve (FLC) of the material. By selecting a point on the process
signature a new FLC is displayed which shows the remaining formability
of the material corresponding to the selected point.
By measuring the grid at different stages during the forming, the
influence from the strain history on the remaining formability can be
taken into account. Examples of the use of the system are given.
|
|
Small lot stamping production by progressive unit dies
|
|
T. Nakagawa (1), S. Futamura, T. Murata
|
|
STC F, 42/1/1993, P.313
|
|
Keywords: Blanking, Hydraulic Presses, Progressive dies |
Abstract : This paper describes a new concept in tooling system and the press
machine for the widely used progressive stamping technology. The usual
conventional progressive die set up is divided into a number of unit
dies performing individual operations. All these unit dies in the system
have been standardized. These dies can be fabricated simply by Wire-EDM.
Consequently, this system is highly suited to small lot stamping
production because the cost of tool making is low and the delivery is quick.
|
|
CNC Hydraulic multipoint blankholder system for sheet metal forming presses
|
|
K. Siegert / E. Doege (1)
|
|
STC F, 42/1/1993, P.319
|
|
Keywords: Sheet Fed Presses, Hydraulic Equipment, Computer Numerical Control (CNC) |
Abstract : Starting with the insufficient pneumatic drawing mechanism (cushion) in
the table of single-action presses, a programmable hydraulic drawing
mechanism is introduced, which makes it possible to control the sheet
metal flow through a controllable blankholder (binder) pressure and
therefore represents a major contribution in reproducible sheet metal
forming processes.
|
|
On the formability of aluminum-coated steel sheet
|
|
K.J. Weinmann (2), S.K. Kernosky
|
|
STC F, 42/1/1993, P.323
|
|
Keywords: Sheet Metal, Formability, Coatings |
Abstract : Mild steel sheet coated with aluminum was characterized in terms of
mechanical behavior and formability. The layer of aluminum, 7 ?m - 10µm
thick, was deposited by a relatively recently developed version of
physical vapor deposition (PVD). The uniqueness of this particular
deposition process comes from the use of a steered arc. The substrate
chosen for the study was deep drawing quality steel of the type used in
the automotive industry. Tension tests provided information on
ductility, strain, and strength. A forming limit diagram (FLD) was
constructed and angular stretch bend tests carried out to assess the
formability of coated sheet.
This study found a 40%37;, increase in the yield stress of coated material
over uncoated material. Additionally, coated material has lower
formability than uncoated sheet. The majority of the properties of the
coated sheet are attributable to strain aging of the steel (diffusion of
carbon atoms to dislocations) brought about by the coating process.
|
|
Ductile failure in upsetting of a rapid solidification processed aluminium-alloy
|
|
F.A.C.M. Habraken, J.H. Dautzenberg (2)
|
|
STC F, 42/1/1993, P.327
|
|
Keywords: Ductility, Upsetting, Aluminium Alloys |
Abstract : Cold upset-tests have been performed on a Rapid Solidification Processed
(RSP) aluminum-alloy, produced by the 'melt-spun ribbons'-process out of
70%37; car-scrap and 30%37; primary scrap. The ribbons are hot extruded,
resulting in 29 mm diameter bar. Its properties regarding plastic flow
and fracture are strongly anisotropic. Upset-tests are performed on this
alloy to verify a concept for the prediction of ductile failure. The
experimental results also demonstrate the mechanical integrity of this
material.
Hill's flow-criterion for anisotropic materials is used in FEM-models of
the experiments. Results of various experiments concerning failure at
the equatorial free surface are compared with fracture strains in
torsion and tension tests in circumferential direction. Furthermore a
surface-instability analysis based on an energy principle is applied. It
is shown that a graph of effective strain versus triaxiality (?_m / ?)
in addition to an instability-criterion, is a useful tool for the
prediction of ductile failure in forming processes.
|
|
A study of the plane strain compression test
|
|
M. Pietrzyk, J.G. Lenard (1), G.M. Dalton
|
|
STC F, 42/1/1993, P.331
|
|
Keywords: Rolling, Compression, Temperature |
Abstract : The applicability of the plane strain compression test to simulate the
flat rolling process is examined, analytically and through experiments.
The resistance to deformation and the rise of temperature of a 6061-T6
aluminum alloy is determined in plane strain compression. A
thermal-mechanical finite element model, developed to analyze both the
rolling and compression processes is then introduced. Its ability to
calculate the distributions of the variables is substantiated by
comparing the time-temperature profiles measured during plane strain
compression tests with those predicted by the model. Following next are
comparisons of the distributions of stress, strain rate and temperature
in the two processes, leading to the conclusion that, in general, good
similarity among the parameters is observed and that the plane strain
compression test gives a reasonable simulation of the flat rolling
process, provided the shape factors are comparable.
|
|
The evaluation of flow stress and friction in upsetting of rings and cylinders
|
|
A. Bugini, G. Maccarini, C. Giardini, R. Pacagnella / R. Levi (1)
|
|
STC F, 42/1/1993, P.335
|
|
Keywords: Forming, Upstetting, Friction |
Abstract : FEM calibration chart for ring upsetting at room temperature is drawn
when dealing with annealed Aluminum specimens of different height. The
method allows the evaluation of the friction coefficient affecting the
plastic flow when teflon films are interposed between dies and specimens.
|
|
Springback reduction in draw bending process of sheet metals
|
|
D. Schmoeckel (1), M. Beth
|
|
STC F, 42/1/1993, P.339
|
|
Keywords: Sheet Metal, Springback, Draw Bending |
Abstract : A model test has been developed in order to examine the springback of
sheet metals in draw bending under combined tensile stresses. The
tensile stress components are of decisive influence concerning the
springback behavior. Therefore, a control of springback is possible with
specially adapted blankholder pressure. Experimental results are
discussed and compared with results of FE simulation.
|
|
Investigation of microstructure and thermomechanical history in the hammer forging of an incoloy 901 disk
|
|
G. Shen, R. Shivpuri, S.L. Semiatin, J. Y. Lee / T. Altan (1)
|
|
STC F, 42/1/1993, P.343
|
|
Keywords: Simulation, Hammer Forging, Nickel Alloys, Microstructure |
Abstract : A method for computer simulation of hammer forging is presented. The
relationship between the observed final gain size in Incoloy 901 disk
forgings and the thermomechanical histories obtained from computer
simulations was established. It is shown that hammer forging can be
modeled with reasonable accuracy by computer simulation and, the
calculated thermomechanical history of material along with known phase
relations can reasonably explain the evolution of microstructure in
forged parts.
|
|
Factors affecting the double cup extrusion test for evaluation of friction in cold and warm forging
|
|
M.I. Ghobrial, J.Y. Lee, T. Altan (1), N. Bay (2), B.G. Hansen
|
|
STC F, 42/1/1993, P.347
|
|
Keywords: FEM Simulation, Double Cup Extrusion, Friction Test |
Abstract : The objective of this study is to expand the double cup extrusion test,
used for evaluating lubrication in cold forging, to determine the
friction factor m and study factors affecting the sensitivity of this
test at the same time. An FEM analysis was used to predict metal flow
and forming load for different reductions in area, using a fixed billet
geometry. Based on this study a procedure is suggested to estimate
friction at large effective strains and interface pressures that occure
in cold and warm forging, and factors affecting the results of this test
are identified.
|
|
New lubricating method for warm forging of steel with boron oxide (B203)
|
|
F. Nonoyama, K. Kitamura, A. Danno / K. Osakada (1)
|
|
STC F, 42/1/1993, P.353
|
|
Keywords: Forging, Lubrication, Hot Forming |
Abstract : Boron oxide (B_2 0_3 ) is a glass with low viscosity in the temperature
range of warm forging. Lubrication properties of B_2 0_3 in warm forging
of steels were mainly examined using the backward can extrusion test. On
the inside surface of a can. a B_2 0_3 film formed on the surface of a
billet contributed to reduce seizure. friction and heat damage of a
punch. For the application of B_2 0_3 , to warm forging, however, it was
required to reduce friction at low temperatures and optimize the amount
of B_2 0_3 , as well as heating conditions. A practical method not only
for satisfying these requirements but also for obtaining high
lubrication properties of B_2 0_3 has been developed. This method was
successfully applied to the production of cans with rectangular cross
sections made of high strength steel.
|
|
Experimental analysis of cut welding in aluminium
|
|
P. Dorph, L. De Chiffre (2), N. Bay (2)
|
|
STC F, 42/1/1993, P.357
|
|
Keywords: Solid State Welding, Aluminium, Strength |
Abstract : Cut welding is a newly developed cold pressure welding process. In the
present work, an experimental investigation was carried out analyzing
the mechanisms involved in cut welding of a block to a strip.
Experiments were carried out in technically pure aluminum. The
investigation has involved tensile testing and metallographic
investigations of the welds. The results show that this variant of cut
welding is a very reproducible process giving a weld strength equal to
30-40%37; the strength of the parent material. The experiments have shown
that the reason for this relatively low strength is an uneven pressure
distribution along the weld due to a wave formed during sliding.
Attempts to alter the material flow during sliding are presented.
|
|
A constitutive model for friction in forming
|
|
L. Anand (2), W. Tong
|
|
STC F, 42/1/1993, P.361
|
|
Keywords: Friction, Forming |
Abstract : A new adhering-slipping constitutive model for interface friction is
outlined. The model is fully three-dimensional in nature, but rate
independent, isothermal and isotropic in character. A new
compression-torsion friction experiment to directly measure
tool-workpiece interface frictional response under conditions
approaching those encountered in quasistatic deformation processing is
described. Specific functional forms for the constitutive equations are
proposed, and methods to evaluate the material parameters in the
interface constitutive model are developed. The particular
workpiece-tool pair for which the material parameters are reported in
this paper is annealed OFHC copper sliding against AISI A2 tool steel.
Although idealized, the model should he useful for a first-order
accounting of frictional behavior at dry, unlubricated contacting
interfaces in quasistatic deformation processing operations of metallic
workpieces with rigid tools.
|
STC G |
|
High-performance surface grinding
|
|
E. Brinksmeier (2), E. Minke
|
|
STC G, 42/1/1993, P.367
|
|
Keywords: Grinding, Grinding Fluids, Cutting Speed |
Abstract : The availability of newly designed grinding machines wish high
stiffness. high spindle power and wheel speeds, super abrasive
CBN-grinding wheels, adaptive dressing techniques, coolant delivery,
coolant filter, and wheel surface cleaning systems enables application
of the high-performance grinding method. This grinding technique, using
CBN-grinding wheels. can be characterized by high cutting speeds.
relatively high material removal rates, and good surface finish. This
paper presents the consideration of chip thickness and its influence on
the grinding process, due to the grinding parameters. such as cutting
speed. depth of cut and work speed. Results obtained in practical
investigations concerning the impact of the coolant delivery, on the
emerged forces and on die power demand at high peripheral wheel speeds
are discussed.
|
|
CBN or CD grinding of profiles
|
|
E. Westkämper / H.K. Tönshoff (1)
|
|
STC G, 42/1/1993, P.371
|
|
Keywords: Cubic boron nitride (CBN), Dressing, Technology assessment |
Abstract : In practice, profiles in difficult-to-machine materials are ground by
means of CD grinding or by using CBN wheels. Both processes permit
manufacturing at high cutting speeds and produce a high shape accuracy
and a high surface quality. In CBN grinding, this is achieved through
the use of vivified bonded or electroplated CBN wheels. The
comparatively low wear of this wheel type allows constant operating
conditions even at high speeds. In CD grinding, conventional grinding
wheels are kept in almost constant condition through continuous
conditioning. However, conditioning reduces the wheel volume to a larger
extent than the normal grinding wear would do. In this paper, the two
grinding processes are compared as to their economical efficiency based
on a specific machining task. In numerous tests, first, the
technological limits of performance were investigated. On the basis of
the test results, a time and cost comparison was made.
It was found for CD grinding that an optimization of the process
parameters led to better results. With a comparable surface quality,
higher material removal rates were achieved. On the contrary, the more
expensive CBN wheels did not possess a sufficient pore volume to be able
to produce comparable results.
|
|
A new grinding method ceramics using a biaxially vibrated non-rotational ultrasonic tool
|
|
K. Suzuki, T. Uematsu, H. Tochinai, S. Mishiro / T. Nakagawa (1)
|
|
STC G, 42/1/1993, P.375
|
|
Keywords: Grinding, Ceramics, Ultrasonics |
Abstract : A new method for grinding ceramics and hard materials by using a
non-rotational tool has been developed. In the method a fixed abrasive
type grinding tool is vibrated by a complex ultrasonic transducer
longitudinally and torsionally at the same time. Experiments showed that
the complex ultrasonic vibration keeps grinding force low and stable for
a long time in grinding hard ceramics even without rotating the tool.
When a diamond grinding tool with a square or triangular bottom is used,
this method has a great effect on producing cavities with sharp inner
corners of almost zero radius on various hard-to-machine materials.
|
|
Intelligent data base for grinding operations
|
|
T. Sakakura, T. Inasaki (1)
|
|
STC G, 42/1/1993, P.379
|
|
Keywords: Grinding, Dressing, Data Base |
Abstract : This paper describes an intelligent data base system which performs an
intelligent task like a skilled operator. The system consists of a
grinding data base, a grinding rule base, a learning module and a
reasoning module. The learning module extracts relationships between
set-up parameters and results from grinding examples stored in the
grinding data base using genetic algorithms. These relationships are
expressed in the Form of a fuzzy production rule and stored in the
grinding rule hase. The reasoning module provides suitable dressing and
grinding parameters using those rules. A computer simulation is
performed to confirm the effectiveness of the proposed system.
|
|
Computer simulation for cylindrical plunge grinding
|
|
N. Chiu, S. Malkin (1)
|
|
STC G, 42/1/1993, P.383
|
|
Keywords: Grinding, Computerized Simulation |
Abstract : A computerized simulation is described tot cylindrical plunge grinding
operations. The simulation predicts both the grinding behavior during
the cycle and the final part quality, including grinding forces, power,
actual material removal, temperature, thermal damage, thermal expansion,
wheel wear, surface roughness and roundness. White not necessarily
predicting the exact performance, the simulation does capture the main
effects which occur during the grinding cycle. The conceptual and
physical construction of the simulation program are described. Examples
are presented to illustrate how the simulation works. Experimental
results are found to compare favorably with predictions from the simulation.
|
|
Computer visual simulation on structural changes of steel in grinding process and experimental verification
|
|
H. Eda, E. Ohmura, S. Yamauchi / I. Inasaki (1)
|
|
STC G, 42/1/1993, P.389
|
|
Keywords: Grinding, Computerized Simulation, Microstructure |
Abstract : A computer simulation system was developed to estimate the heat-affected
zone (HAZ) of carbon steel in surface grinding process. HAZ is usually
generated by solid state phase transformation causes by the grinding
temperature. In the present system, the heat flow and phase
transformation during grinding process was analyzed using a
finite-difference method. The changes with the time of temperature
distribution, the carbon redistribution in austenite and the quenching
to martensite were simulated or, an engineering work station (EWS). The
simulated results of the distributions of temperature, microstructure
and carbon concentration were shown in the pseudocolor images on the
display. Furthermore, experimental surface grinding was carried out and
the results were in good agreement with the simulated results.
|
|
An intelligent monitoring system for cylindrical grinding
|
|
P. Lezanski,J. Rafalowicz / J. Jedrzejewski (1)
|
|
STC G, 42/1/1993, P.393
|
|
Keywords: Cylindrical Grinding, Process Monitoring, Data Processing |
Abstract : A sensor based system for process state monitoring during cylindrical
grinding is described. A modular and hierarchical structure with a
multiple-sensor approach (cutting forces, vibration, acoustic emission,
and both diameter and out-of-roundness of the workpiece) for process
monitoring has been proposed for the system. Features are extracted from
the sensor readings by signal processing. They form a set of data which
makes it possible to evaluate the grinding process in every respect
because the signals represent different groups of process features. The
problems associate with the signal processing rind recording are discussed.
|
|
Abrasive texturing and bursnishing process monitoring using acoustic emission
|
|
D.A. Dornfeld (2), J.J.B. Liu
|
|
STC G, 42/1/1993, P.397
|
|
Keywords: Acoustic Emission, Burnishing, Process Monitoring |
Abstract : This paper evaluates the use of acoustic emission (AE) feedback as a
method to monitor and control the tape burnishing process. A brief
review of the research on friction and wear studies using AE, which
provides the basis for this investigation, is first presented. A fluid
coupled AE sensor is used to monitor the extent of texturing in a thin
film rigid magnetic storage disk manufacturing process. Normal and
friction forces are also measured for comparison to the AE. A strong
correlation was found between characteristics of the disk texture
(surface profile and roughness) and parameters of the AE signal (RMS
voltage, mean frequency, zero crossing rate and spectral density.) The
feasibility of using AE for tape burnishing monitoring is established.
|
|
In-process measurements of progressive variation of grinding characteristics in constant-load heavy grinding
|
|
T. Natsuo (1), M. Touge, K. Iwasaki
|
|
STC G, 42/1/1993, P.401
|
|
Keywords: Grinding, Material Removal, Self-Sharpening |
Abstract : Constant-load heavy grinding was performed on 304 stainless steel with
three different alumina wheel types. The variation of grinding
characteristics such as removal rate and tangential force with the
progress of grinding, has been studied using in-process measuring
methods. It was obvious that removal rate, wheel rate and tangential
force changed remarkable with grinding tome, and there are closed
correlations each other. Wear flat area of abrasive grains were also
measured. The variations of grinding characteristics have been explained
well with the progressive wear and the generation of self-sharpening.
|
|
Measurement of grinding temperature of active grains using infrared radiation pyrometer with optical fiber
|
|
T. Ueda, H. Tanaka, A. Torii, T. Sugita / T. Matsuo (1)
|
|
STC G, 42/1/1993, P.405
|
|
Keywords: Grinding, Temperatures, Measurements |
Abstract : The temperature of the cutting grains on the grinding wheel just after
cutting is measured using a new type of infrared radiation pyrometer
with optical fiber and InAs cell. The mean temperature of cutting grains
is hardly influenced by the wheel depth of cut or the workpiece speed,
but decreases with increase of the wheel speed. The maximum temperature
of cutting grains at the cutting point is approximate to the melting
point of the work material of steel. The change in the working
conditions of cutting grains after every revolution of the wheel is
observed.
|
|
The effect of deformation on the contact area in grinding
|
|
W.B. Rowe (1)
|
|
STC G, 42/1/1993, P.409
|
|
Keywords: Grinding, Modelling, Contact |
Abstract : Grinding efficiency and workpiece surface integrity are greatly affected
by deflections that occur within the grinding contact zone. This paper
is concerned with the effect deflections have on the real length of
contact. A new relationship for the contact between the grinding wheel
and the surface of the workpiece is introduced based on contact
mechanics. The real contact length between the grinding wheel and the
workpiece has been modeled based on the theory for cylinders in contact
including the effect of the surface roughness of the contact faces. A
.second formulation is presented which takes account of the contact area
at the micro level of the grains. The new model more accurately
describes the mechanics of grinding contact than previous contact
models. Application of the new model to published experimental data for
plunge surface grinding operations explains why measured contact length
can be 50%37; - 200%37; greater than the geometric contact length.
|
|
On improved bonding of TiC coated CBN grits in nickel based matrix
|
|
A.K. Chattopadhyay, H.E. Hintermann (1)
|
|
STC G, 42/1/1993, P.413
|
|
Keywords: Grinding, CBN, Bonding |
Abstract : The present work has shown that galvanically bonded CBN abrasive tools,
particularly those with monocrystalline CBN particles having relatively
smooth surface may suffer from large grit pull out during grinding. This
investigation has further revealed that strong and durable Ni-Cr alloys,
which are known to braze uncoated diamond grits very effectively,
providing superior bond than galvanic one, however, failed to wet
uncoated CBN crystals during brazing. Thus, in order to activate Ni-Cr
alloys, surface modification of CBN grits was found to be essential. To
achieve this, a new process has been developed, wherein the CBN
particles were coated with a strongly adherent film of TiC by
conventional CVD. Such surface modification significantly improved
retention of CBN grits in Ni-based matrix.
|
|
Ultra-precision grinding of optical glasses to produce super-smoots surfaces
|
|
Y. Namba, M. Abe / A. Kobayashi (1)
|
|
STC G, 42/1/1993, P.417
|
|
Keywords: Ultra-Precision Machining, Diamond Wheels, Optical Surfaces |
Abstract : The typical 11 kinds of optical glasses have been ground by the
ultra-precision surface grinder having a glass-ceramic spindle of
extremely-low thermal expansion with various cup-typed resinoid-bonded
diamond wheels of #200-#3000 in grain size. All kinds of glasses can be
ground in the ductile mode and the surface does not contain a
micro-crack under the surface. The surface roughness is related with
grain size, feed per wheel revolution and glass material, not with depth
of cut. Super-smooth surfaces less than 0.2nm rms, 2nm Rmax have been
obtained by the ultra-precision grinding.
|
|
Proposal of new lapping method for ceramic balls
|
|
S. Ichikawa, H. Ona, I. Yoshimoto / A. Kobayashi (1)
|
|
STC G, 42/1/1993, P.421
|
|
Keywords: Lapping, Ceramics, Spheres |
Abstract : This paper treats the relation among lapping pressure,
wear-distance-ratio, mesh number of abrasive sheet and sphericity of
balls in the lapping circumstances off ceramic ball, and the mew lapping
method for ceramic balls are presented. Obtained results are as follows:
(1) For balls formed by CIP the optimum lapping conditions such as
lapping pressure, the mesh number of abrasive sheet and others are
found. (2) New lapping method for sintered ball based on the three-point
measuring method of roundness measuring method is proposed, and the
sphericity of balls can be considerably improved by this method. (3) The
optimum share ration of normal loads in combined tools is found for the
rapid improvement of the sphericity of balls.
|
|
The new method of free form surface honing
|
|
B. Nowicki / M. Szafarczyk (1)
|
|
STC G, 42/1/1993, P.425
|
|
Keywords: Honing, Sculptured Surface |
Abstract : The finishing of free-form surface such as press forming dies,
propellers, screw propellers is usually a manual job or is done by
robots equipped with special machining heads
The author has elaborated the non-conventional method of honing which
enables to place the profiling and the finishing one the same machine
tool. The abrasive tools have 4 degrees of freedom, they are elastically
pressed against the surface Their working surfaces are always tangent to
the machined surface The elaborated method is suitable for machining
parts of various plasticity. The minimum allowable curvature radii of
the machined parts is 40 mm, the removal rate is about 1 dm²/min and the
surface roughness after machining is Ra=0 05-1.5 mm.
|
STC M |
|
Design and modelling of a modular robot system
|
|
P.C. Mulders (2), G.J. Kreffer, W.H.M. Bax, A.C.H. Van Der Wolf (1)
|
|
STC M, 42/1/1993, P.429
|
|
Keywords: Mechatronics, Simulation, Computer Adaptive Control |
Abstract : A modular robot system - consisting of a linear and a rotary actuator
and for loads up to 50 kg - has been developed. The linear robot arm is
driven by a DC motor, has a length of 1 m. a maximum velocity of 1 m/s,
an acceleration of 5 m/s², and an accuracy of 0.01 mm. The rotational
module is also driven by a DC motor with an angular velocity of P/'2
rad/s, an acceleration of P /2 rad/s^² and an accuracy of 10^-5 rad.
With a 3D-force sensor teach - and replay of trajectories will be performed.
Optimal trajectory control strategies - like e.g. the optimal control
law by matrix riccati, the computed torque or model reference adaptive
control (MRAC) method - are based on a good knowledge of the system.
So from this modular robot an extended dynamic model has been made,
which is verified by modal analysis techniques.
Next a model reduction has been done - to obtain a simulation model or a
control model - and this is necessary to test adaptive path control
algorithms with respect to the phenomena of parameter variations during
trajectory performance.
|
|
SHIVA a multi-arms machine tool
|
|
O. Garro, p. Martin (2), M. Véron (1)
|
|
STC M, 42/1/1993, P.433
|
|
Keywords: Machine Tool, Design, Optimization |
Abstract : In this article we present a new model of machine toot with higher
performance in terms of productivity and flexibility. The prototype of
this machine toot is called SHIVA because of its great number of axes
and operative parts. We define a methodology of design for these
machines based on the use of manufacturing features. Finally we present
a comparison between this machine and the classical ones.
|
|
Evaluation of a lathe with ferrocement bed
|
|
M. Rahman (2), M.A. Mansur
|
|
STC M, 42/1/1993, P.437
|
|
Keywords: Machine Tools, Ferrocement Bed, Centre Lathe, Cutting Tests, Performance Evaluation, Vibration Tests |
Abstract : In an earlier study, the feasibility of using ferrocement as a
replacement to cast iron in the manufacture of machine tool structures
was investigated by fabricating a prototype ferrocement bed for a centre
lathe and testing the bed alone. Improved performance exhibited by the
ferrocement bed in comparison with the parent cast iron bed under both
static and dynamic loadings has inspired the authors to pursue the work
and assess the bed in terms of the performance of the machine as a whole.
A centre lathe was chosen for this purpose. The traditional cast iron
bed in the machine was replaced by a ferrocement bed, designed and
fabricated for accommodating all the necessary parts and attachments.
The method of fabrication and installation of the bed are described in
this paper. Identical vibration and cutting tests were performed in the
original as well as the modified machines. Test results indicate that
the machine with ferrocement bed provides significantly higher damping
and natural frequencies, specially the torsional frequency, and results
in an approximately 40%37; deeper cut than the original lathe before the
onset of chatter.
|
|
Research on machine tools rolling slideways assembly with damping oil-films
|
|
Q.Y. Wang, Z. Jiang, W.M. Qian, H.S. Qi / H.W. Zheng (1)
|
|
STC M, 42/1/1993, P.441
|
|
Keywords: Machine Tools, Damping Oil-Films, Rolling Slideways |
Abstract : This paper presents an investigation on inserting damping oi1-films into
machine tools rolling slideways. It indicates that the vibration-proof
ability of the system can be improved significantly by this means as
well as its proper moving sensitivity and low-speed moving stability are
preserved. The experimental formula of the damping coefficient of
rectangular oil-films with a parallel gap is presented through tests.
The rolling slideways system with damping oil-films is modeled in
accordance with the special characteristic of the structure and the
corresponding identification method of the damping coefficient is
presented. Furthermore, computer simulative experiments are carried out.
On the basis of the analysis of the results the objective for
optimization of oil-film damping parameters is given.
|
|
Spindle bearing systems for high speed applications in machine tools
|
|
M. Weck (1), A. Koch
|
|
STC M, 42/1/1993, P.445
|
|
Keywords: Spindles, Lubrication, Roller Bearings |
Abstract : The operational speed of spindle bearing systems with angular contact
ball bearings is limited amongst other factors by the highest
permissible rotatory speed of the bearings The revolution parameter
limit of these bearings currently lies at about n*dm=1.5*10^6 mm/min if
lubricated by the principle of minimum oil quantity. This paper will
introduce how, by applying oil-air minimum quantity lubrication using a
new oil-air supply, the revolutionary parameter limit was able to be
increased to approximately n*dm=1.8*10s mm/min. On the basis of test
results it shows how the application of ceramic balls or coated bearing
elements reduces the surface wear under insufficient lubrication
conditions and increases the life span of the bearing.
|
|
Open system controllers, a challenge for the future of the machine tool industry
|
|
G. Pritschow (1), C. Daniel, G. Junghans, W. Sperling
|
|
STC M, 42/1/1993, P.449
|
|
Keywords: Machine Tools, NC Controllers, Open System Architecture |
Abstract : This contribution deals with the present situation of the European
machine tool industry and the control manufacturers as well, as with the
motivation to start with the design of a vendor-neutral open control system.
The problems of configuration and control-internal communication are
discussed and solutions are given. Furthermore, the ESPRIT project OSACA
is presented which aims at the specification of vendor-neutral standards
for open control systems.
|
|
Polynomial predictive functional control (PPFC) for motor drives
|
|
P. Boucher (2), D. Dumur (2), H.P. Kurzweil
|
|
STC M, 42/1/1993, P.453
|
|
Keywords: Machine Tools, CNC, Control System |
Abstract : Among the field of predictive technics, Predictive Functional Control
seems to be very attractive for non specialists of predictive control
methods, due to its simple tuning, and well adapted to C.N.C. machines.
This different approach is presented here in a polynomial form called
Polynomial Predictive Functional Control (P.P.F.C.) to provide a
stability analysis and a simple design of the tuning parameters. The
developed version improves classical solutions by including a control
weighting factor to avoid high values of the control signal.
The new P.P.F.C. is finally used for the velocity control of motor
drives and experiments stress the advantages of this method in terms of
simple design and robustness, compared to previous results obtained with
Generalized Predictive Control.
|
|
Collision free five axis milling of twisted ruled surface
|
|
F. H. Rehsteiner, H.J. Renker (1)
|
|
STC M, 42/1/1993, P.457
|
|
Keywords: Cutting Path, Milling, Surfaces, Geometry |
Abstract : Ruled surfaces (generated by straight ruling lines) are a special kind
of free form surfaces which plays an important role, e.g., in
aerodynamic surfaces (rotary engines). They are particularly well suited
for five axis milling by the flank milling method. In the case of
twisted ruled surfaces, however, the obvious milling method of having
the cutter touch these ruling lines along a generator of its own flank
leads to collision problems,
The nature of these twisted ruled surfaces is analysed and conditions
for their collision free milling by a cylindrical cutter are
established. Efficient milling strategies are found.
|
|
Efficient simulation programs for chatter in milling
|
|
S. Smith, J. Tlusty (1)
|
|
STC M, 42/1/1993, P.463
|
|
Keywords: Milling, Chatter |
Abstract : This paper outlines the use of PTP (peak-to-peak) diagrams for the
evaluation of the results of multiple runs of a time-domain simulation
of a milling process. These diagrams summarize the amplitudes of the
forces, deflections, or surface finishes resulting from a large number
of simulations through a range of axial depths of cut and spindle speed.
The diagrams have similarities to and contain the global information of
the familiar stability lobe diagrams, while including the detail
available from simulation.
|
|
Screw presses with a flywheel inertia variable moment
|
|
D. Temeljkovski, p. Popovic / V. Solaja (1)
|
|
STC M, 42/1/1993, P.467
|
|
Keywords: Screw Presses, Conceptual Model, Load Control |
Abstract : Starting from the theoretically made complex model of screw presses the
authors present a new driving system which is designed in order to
provide available energy variations. After mathematical modeling and
computer-aided simulation the experimental research is carried out on
the laboratory model. The model control is done by microprocessor. The
obtained results of the theoretical and experimental research arc a
solid foundation for designing screw presses of changed conceptual
solutions which will have a higher degree of compatibility of the
machine capabilities and the technological processes requirement
according to energetic parameters.
|
|
Environmentally clean machining processes - A strategic approach
|
|
G. Byrne (2), E. Scholta
|
|
STC M, 42/1/1993, P.471
|
|
Keywords: Machining, Environmental Impact |
Abstract : Present day machining processes are not clean. Current trends in the
manufacturing world indicate that this situation will not be acceptable
in the Future and that extensive research and development work is
essential in order to meet the future requirements of legislation
In this paper, the various possible routes to achieve clean machining
processes are analyzed and discussed. It is shown that the conventional
approach has its limitations and that a new and innovative approach is
essential within the framework of an environmentally oriented management
system and the relevant networks for data provision and analysis
Processes have to be subjected to fine analysis giving detailed
consideration to the various inputs and outputs Combined processes,
alternative processes, new technologies, energy requirements etc. have
to be evaluated from the environmental perspective A first approach to
the strategy required to answer the many questions which arise in
relation to clean machining processes and to an integrated environmental
protection policy is presented and discussed
|
STC O |
|
Development of a virtual manufacturing system by integrating product models and factory models
|
|
M. Onosato, K. Iwata (1)
|
|
STC O, 42/1/1993, P.475
|
|
Keywords: Manufacturing System |
Abstract : Virtual manufacturing (VM) is a concept of executing manufacturing
processes in computers as well as in the real world. VM makes it
possible to estimate manufacturing processes previously without using
real facilities, and therefore, VM is expected to be used for many
applications in manufacturing. This paper firstly introduces the concept
of VM systems and discusses the relations with other concepts in
manufacturing. After the discussion about the requirements for VM
systems, the architecture of VM systems is explained. Lastly, some
systems developed for VM systems are introduced.
|
|
Modelling flexible manufacturing systems based on Petri nets
|
|
H. Van Brussel (1), Y. Peng, p. Valckenaens
|
|
STC O, 42/1/1993, P.479
|
|
Keywords: Flexible Manufacturing Systems, Modelling |
Abstract : Petri nets have evolved into a powerful too: for analysing asynchronous
concurrent systems. In this paper the Petri net formalism is used for
developing modular models of flexible manufacturing systems (FMS).
Coloured-Timed Extended Petri nets are used to model the shared
resources, the precedent constraints of the products to be fabricated in
the PMS, as well as the automatic transport system of the FMS. A
systematic approach to generate the Petri net model for the FMS is
proposed and implemented. The resulting Peen net models serve as a
simulation tool for scheduling optimization.
|
|
A step towards intelligent manufacturing : modelling and monitoring of manufacturing processes through artificial neural networks
|
|
L. Monostori / J. Prohaska (1)
|
|
STC O, 42/1/1993, P.485
|
|
Keywords: In-Process Monitoring, Tool Wear, Neural Networks |
Abstract : In the paper different approaches are described for applying artificial
neural network techniques for modeling and monitoring of machining
process (turning, milling) by sensor integration. Back propagations
network are used for state classification of tools, estimation of the
tool wear and inverse modeling of the cutting process. Special emphasis
is placed on the incorporation of the varying cutting conditions into
the learning phase and solution, which are based upon normal operation,
i.e. cutting with sharp tools. Performances of the developed strategies
are demonstrated and compared. At the end of the paper the role and
perspectives of artificial neural networks in intelligent manufacturing
are highlighted.
|
|
A software architecture for FMS simulation and control
|
|
A. Del Taglia / M. Santochi (1)
|
|
STC O, 42/1/1993, P.489
|
|
Keywords: FMS, Control, Simulation |
Abstract : Control software for an FMS is normally tailored on a specific plant:
this causes long development times and high costs; hence the
impossibility to have the software at the early stage of the system
design and the difficulty of modifying the software during the working
phase. The paper describes a software architecture that allows the
interactive definition of an FMS model and, at the same tine,
automatically builds the control and emulation software. These,
together, constitute an off-line detailed simulator that may be used for
plant optimization. When the plant is completely set up, the control
software is also available; when the plant is functioning, the
simulation software may be used as on-line simulator for the decision
rules optimization.
|
|
Conceptual design of a relational data base for manufacturing processes
|
|
S. Kastelic, J. Kopiac, J. Peklenik (1)
|
|
STC O, 42/1/1993, P.493
|
|
Keywords: Relational Data Base, Machinability Data, Optimization |
Abstract : An effective CA-process planning and the optimization of conditions
depend significantly on the quality and availability of the
machinability data for various manufacturing processes. The contribution
explains the conceptual design of a relational data base, its structure
and the standard procedures for using the data in CAPP, NC-programming
and other preparatory operations for production. An illustrative example
reveals the viability of the design of the data base and the procedures
of optimizing the turning operations.
|
|
RALB - A heuristic algorithm for design and balancing of robotic assembly lines
|
|
J. Rubinovitz, J. Bukchin / E. Lenz (1)
|
|
STC O, 42/1/1993, P.497
|
|
Keywords: Robotic Assembly, Line Balancing, Frontier Search |
Abstract : This paper describes an heuristic approach for design and balancing of a
robotic assembly line. The objective of RALB (Robotic Assembly Line
Balancing) algorithm is to balance the assembly line, by allocating
equal amount of work to the stations on the line, while assigning the
most efficient robot type, out of several different types of robots
available for the assembly task, to each workstation, and minimizing the
number of workstations and robots used. RALB uses heuristics to limit
and guide a Branch and Bound frontier search, thus leading to solution
of very large or difficult problems. A recommendation of the optimal set
of heuristic rules is made based on results of extensive testing of RALB
with a variety of assembly problems.
|
|
A two-stage approach for optimizing simulation experiments
|
|
N.C. Ho, S.S.G. Lee, Y.L. Loh / A.Y.C. Nee (1)
|
|
STC O, 42/1/1993, P.501
|
|
Keywords: Simulation, Optimization |
Abstract : Simulation experiments involve many parameters (factors) not all of
which significantly affect system performance. This paper proposes the
application of Taguchi method prior to optimization, to reduce the
number of experiments using orthogonal array design, and to determine
the significant factors through sensitivity analysis. Non-linear
optimization search strategies are then used to determine the 'optimal'
level of these factors. This approach, besides being straightforward,
can optimize both quantifiable and non-quantifiable factors and also
reduces optimization time. Results from initial studies support its
effectiveness in the optimization of simulation systems.
|
|
Lower and upper bounds of manufacturing cost in FMS
|
|
S. Noto La Diega (2), A. Passannanti, U. La Commare (2)
|
|
STC O, 42/1/1993, P.505
|
|
Keywords: Optimization, FMS,Cost Analysis |
Abstract : The use of traditional techniques of product costing, cost control and
performance evaluation in advanced manufacturing environment supplies
poor results to operations management. In this paper, after a brief
review of the major drawbacks traditional machining economics, a new
framework for product costing will be presented.
The basis of the proposed approach lies on an analysis of the production
process aimed at single out proper cost drivers for the use of the
various employed manufacturing resources. As a consequence, the quota of
the manufacturing cost of uncertain allocation is drastically reduced. A
lower and au upper bound value of the unit production cost are also
defined with reference to the given manufacturing system. The range
between the above bounds is used for accounting the costs of uncertain
allocation.
|
|
Logistics performance measurement of shop floor activities
|
|
H.P. Wiendahl (1), W. Ullmann
|
|
STC O, 42/1/1993, P.509
|
|
Keywords: Production Logistics, Performance Measurement, Monitoring System |
Abstract : The way to 'World Class Manufacturing' often suffers from the lack of
objective performance criteria on shop floor level. We introduce new
approaches for the logistics evaluation of production by means of a
specific performance measurement (P.M.): monitoring methods support the
analysis of production and order flows and structures, allowing for a
quantified turn to account of hidden potentials. On this basis,
company-wide accepted information systems with illustrative graphics
help to keep on-track with consistant and realistic defined goals.
|
|
IPPM - A prototype to integrate process planning and job shop scheduling functions
|
|
H.C. Zhang / E. Merchant (1)
|
|
STC O, 42/1/1993, P.513
|
|
Keywords: CAPP, Production Scheduling, Functional Integration |
Abstract : Functional integration has taken the foreground in the current
manufacturing system development. Process planning and job shop
scheduling we two main manufacturing functions involved in shopfloor
activities. An integrated process planning model (IPPM) is introduced in
this paper. The two functions (process planning and job shop scheduling)
are truly integrated by means of distributed approach which is different
from current nonlinear and alternative process planning approaches. In
this paper, the two functions are integrated at task stage, while the
nonlinear and alternative approaches are taken place at result stage
which cannot be considered as real integration but rather interface. The
introduced IPPM works in three levels, based on manufacturing resource
availability and real time feedback from shop floor they are:
pre-planning, pairing planning, and final planning. The IPPM consists of
three modules, introduced in detailed in the paper, they are: process
planning module, production scheduling module, and decision making
module. An example is provided to illustrate the model. This paper is to
be considered as a contribution to the research efforts in process
planning and integrated manufacturing.
|
|
Intelligent support mechanisms in adaptable human computer interfaces
|
|
D. Spath / H. Weule (1)
|
|
STC O, 42/1/1993, P.519
|
|
Keywords: Computer Systems, Human Factors Engineering, Conceptual model |
Abstract : Advanced production technology is not only characterized by higher
automation of production flow and control, but more and more measured at
the level of the ergonomics of man-machine interaction. Although much
effort has been devoted to user friendly design and improved interface
techniques, today's systems do not take into account their individual
user's problems and tasks. One possible answer to this problem is the
design of 'cooperative', adaptable or adaptive user interfaces. The idea
proposed is to adapt interface behavior (presentation and dialog
control) on account of individual user differences or user problems, by
reasoning about user intentions in situational work contexts.
This paper presents the theory behind and an approach for design of
adaptable/adaptive human-computer interfaces for software applications
in the field of production technology, exemplified by a shop floor
technology planning tool.
|
|
The application of Features in airframe component design and manufacturing
|
|
J.H. Kappert, F.J.A.M. Van Houten(2), H.J.J. Kals (1)
|
|
STC O, 42/1/1993, P.523
|
|
Keywords: images/cirpfichiers/annals/ CAD/CAM |
Abstract : This paper discusses recent results obtained from the development of a
CAD/CAM application, which supports the generation of the manufacturing
information for airframe components, which are produced using the rubber
pad pressing technique. It describes the design module, which has been
developed to generate feature based product models. The feature based
approach guides the designer in creating product models according to
company rules. These models represent the input for the subsequent
modules for manufacturability analysis and tool design. The features are
implemented as extensions to the data structure of a commercial
geometric modeler. The functionality of the manufacturability and tool
design modules are briefly discussed to clarify the demands these
modules put on the product model. It is shown how high level design
modifications can be supported using die proposed product model.
|
|
On the automatic generation of set-ups given a feature-based design representation
|
|
F.L.M. Delbressine, R. De Groot, A.C.H. Van Der Wolf (1)
|
|
STC O, 42/1/1993, P.527
|
|
Keywords: Optimisation, Process-Planning, Computer Integrated |
Abstract : Manufacturing (CIM)
A design methodology has been developed which takes manufacturing
restrictions into account in the geometric design phase. This has been
accomplished by defiling Manufacturable design transformations. A
Manufacturable design transformation is a design operation which has one
or more manufacturing operations as counterpart. The applied design
operations are recorded in a Design Tree which is an integral part of
the product model. Process planning converts this Design Tree, given the
available manufacturing machines, fixturing tools and machining tools,
into a Manufacturing Tree. The Manufacturing Tree consists of one or
more set-ups with per set-up a collection of basic manufacturing
operations. This paper deals with the automatic generation of set-ups
given a design representation based on Manufacturable design
transformations. The main advantage of this approach is a faster
generation of set-ups. Furthermore, the generated set-tips and the
collection of basic manufacturing operations per set-up can be used for
automatic generation of NC code.
|
|
Generation of machining scenario and its applications to intelligent machining operations
|
|
S. Takata (2)
|
|
STC O, 42/1/1993, P.531
|
|
Keywords: Machining, Simulation, Modeling |
Abstract : A machining scenario is a description of a machining process in which
the changes of machining states are described in terms of both
geometrical and physical characteristics of machining processes such as
geometry of tool-workpiece contact face, cutting force, and machining
error. A machining scenario can be automatically generated by a model
based cutting simulation. It provides useful information for pre-process
optimization of cutting conditions, on-line adaptive control, and
monitoring and diagnosis of abnormal occurrences. This paper describes
the data structure of the machining scenario and how it can be utilized
for the generation of efficient and reliable machining data and
realizing intelligent machining operation. The results of experiments by
a prototype system are also described to verify its effectiveness.
|
|
SITS - A semi-intelligent tool selection system for turned components
|
|
S. Hinduja, G. Barrow (1)
|
|
STC O, 42/1/1993, P.535
|
|
Keywords: Optimization, Tool Selection, Turning |
Abstract : A method of selecting tools for the manufacture of turned components is
describes. The system, which is user-friendly, is capable of dealing
with all the operations normally associated with the manufacture of
turned components.
The tools, particularly those for external turning operations, are
chosen so that optimum economic performance eg minimum cost is achieved.
While the system does include a number of automatic routines and is, in
fact, capable of automatically selecting the tools, the user can
interact with it and override the system choice. However, if the system
is overridden the user is informed of any increase in cost caused by the
choice of an alternative tool or tools.
|
|
Principles of multidisciplinary cooperation in research
|
|
A. Kjellberg / G. Sohlenius (1)
|
|
STC O, 42/1/1993, P.541
|
|
Keywords: Behavioural Science, Manufacturing Technology, Multidisciplinary Cooperation |
Abstract : This paper introduces a framework for systematically and strategically
using behavioral sciences in order to achieve more far reaching results
from long-term, visionary technical R & D work. The framework describes
the most important aspects of interdisciplinary work, which are: the
"integration components" and the "integration dimensions" for achieving
the utmost level of integrated, cooperative work. Reflecting upon 20
years of empirical data it is clear that different levels of integration
during the research process will lead to different types of reports with
a predetermined quality - as to the achieved multidisciplinary
integration. Furthermore, the successive specification of the framework
and its application - "the total integration principle", developed for
long-term R&D work - resulted in a research tradition change.
|
|
An opportunistic approach to process planning within a concurrent engineering environment
|
|
A. Herman, M. Lawley, S.C.Y. Lu (2), D. Mattox
|
|
STC O, 42/1/1993, P.545
|
|
Keywords: CAPP, Concurrent Engineering, Life Cycle |
Abstract : Traditionally, design and manufacturing activities have been serially
linked by the process planning function. One objective of concurrent
engineering is to transform this sequential approach into a more
interactive, parallel process. To support concurrent engineering,
computer-aided process planning (CAPP) systems must be developed that
support an opportunistic style of process planning. This paper presents
XTURN, a CAPP system implemented within the IDEEA environment that
supports a flexible and opportunistic style of process planning. XTURN
enables engineers to explore alternative process plans in early design
stages. The engineer controls process selection strategies, while XTURN
determines the interactions between the various choices, flags those
that are inconsistent, and offers advice on resolving any
inconsistencies. XTURN does not require that an inconsistency be
immediately removed, rather it remembers the inconsistency and allows
the engineer to continue exploration. This paper describes the
development and application of XTURN and IDEEA. Also, ongoing research
that extends IDEEA into a fully distributed system integration workbench
to support concurrent engineering is discussed.
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Development of an intelligent machining center incorporating active compensation for thermal distortion
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Y. Hatamura, T. Nagao (2), M. Mitsuishi, K.I. Kato, S. Taguchi, T. Okumura, G. Nakagawa, H. Sugishit
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STC O, 42/1/1993, P.549
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Keywords: Machining Centers, Deformation, Neural Networks |
Abstract : An intelligent machining center that employs thermal actuators to
actively compensate for thermal deformation has been designed,
constructed and tested. The machining, center also incorporates an
intelligent controller, force and deformation sensors and fail-safe
mechanisms to protect against catastrophic failure of the system. Both
matrix control techniques and neural network approaches to the control
of the thermal deformation of the machine structure have been tested. In
both cases, the measured maximum thermal deformation was controlled to a
level of 10 micrometers, approximately 1/3 the level of the uncontrolled
machine.
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Automation of polishing process for a cavity surface on dies and molds by using an expert system
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K. Saito (2), T. Miyoshi, T.Sasaki
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STC O, 42/1/1993, P.553
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Keywords: Expert Systems, Dies, Polishing |
Abstract : In order to establish an automatic manufacturing system for dies and
molds, a surface finishing technology for free form surface must
primarily be developed, because the cavity surface is still finished by
handiwork of a skill machinist. In this paper, the knowledge of skilled
machinists for mold polishing operation was acquired, and an expert
system to design the polishing process was established. This system was
confirmed to be useful for schedule and determination of the polishing
process, and it was verified that performance of this system was similar
to expert performance of mold machinist.
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Development of computer aided inspection system with CMM for integrated mold manufacturing
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H.J. Pahk, Y.H. Kim, Y.S. Hong, S.G. Kim (2)
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STC O, 42/1/1993, P.557
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Keywords: CMM, Molds, CIM |
Abstract : An interactive and integrated inspection system has been developed for
molds having sculptured surfaces with some basic features, such as:
holes, slots and bosses. Features to be inspected can be chosen in the
CAD environment. Then the inspection planning is to be done for each
feature, respectively. For the accurate measurement of sculptured
surfaces, the distribution of measurement points can be controlled to be
uniform, curvature dependent or hybrid of the two. The output of the
planning is the machine code for a specific CMM having CNC capability.
The measured data are to be transferred back to the CAD system,
compensated by the form error calculation, and the evaluated errors are
displayed graphically. High degree of CAD/CAM/CAI integration is
demonstrated by implementing the developed system to real molds.
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Representation of process planning knowledge for part families
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M. Mäntylä / G. Sohlenius (1)
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STC O, 42/1/1993, P.561
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Keywords: Computer Automated Process Planning (CAPP), Knowledge Based Systems, Group Technology |
Abstract : The paper describes the representation of process planning knowledge
utilized in a process planner under development at the Helsinki
University of Technology. The planner puts special emphasis on the
representation and processing of group technological part families. Part
families are represented on the basis of a feature model which is
associated with a family-specific plan specification encoded in a block
structured definition language. The plan specification can be evaluated
at planning time to yield a process plan. The evaluation process
encapsulates the search amongst predefined alternatives and the required
consideration of part instance-specific knowledge. The work is
considered a contribution to computer-aided process planning methodology.
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Computer-aided tool material selection for metal cutting operations
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R.G. Fenton (1), M.F.J. Gagnon
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STC O, 42/1/1993, P.565
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Keywords: Optimization, Cutting-Tool Material, Process Planning |
Abstract : A computer based methodology is presented for cutting-tool material
selection, using numerical optimization for solving the multi-objective
optimization problem. For each cutting-tool material, the feasible set
of optimal solutions are determined and plotted, using computer
graphics, in criteria space (unit production time vs. unit cost). The
best solution for each available tool material is then selected, and the
best overall tool material, corresponding to the optimal criteria
values, together with the optimal cutting parameters, are determined.
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Process oriented organisation of order processing : a new method to meet customers demands
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W. Eversheim (1), St. Krumm, Th. Heuser, St. Müller
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STC O, 42/1/1993, P.569
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Keywords: Process Identification, Process Model, Order Processing |
Abstract : Today's world is continuously changing. High quality and flexibility as
well as low production costs are still important, but these demands
nowadays have to be extended by organizational aspects. However, a
process oriented organization of customer-led order processing from
order receiving to shipping can be seen as a key factor for the future.
Therefore, it is necessary to gain a process model of activities
(processes) to be done in a company. In this case a model has been
developed at WZL, which can be used to build up order processing, to
identify organizational problems, and to simulate lead times.
Additionally work is done in order to use this model for order planning
and control and to build up new process oriented cost accounting methods.
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STC P |
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An advanced metrology system
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W.T. Estler, Y.H. Queen / J. Bryan (1)
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STC P, 42/1/1993, P.573
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Keywords: Metrology, Angular Measurements, Calibration |
Abstract : We describe the new Advanced Automated Master Angle Calibration System
(AAMACS) at the U.S, National Institute of Standards and Technology. The
heart of this system is a set of three stacked concentric indexing
tables with 832, 729, and 625 teeth respectively. The system is fully
error corrected and achieves a full-circle positioning accuracy of =
0.02 arc-seconds with an angular positioning resolution of 0,0034
arc-seconds. System accuracy is limited by autocollimator noise. We will
describe the error mapping process and the use of the system for
high-accuracy autocollimator calibrations.
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Compensation for errors introduced by non-zero fringe densities in phase measuring interferometers
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C.J. Evans / J. Bryan (1)
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STC P, 42/1/1993, P.577
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Keywords: Interferometers, Optical Measurement, Optical Surfaces |
Abstract : Interferometers offer rapid full aperture measurement of optics. Flats,
spheres and conics can be measured to high accuracy with computer
controlled systems using high density detectors. In principle, aspheres
that depart from the base sphere or conic by several micrometers could
also be measured. This paper demonstrates that substantial errors may be
incurred and describes simple tests to evaluate the scale of those
errors. The paper then discusses the error sources and presents a method
for compensating for those errors.
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An accurate interference refractometer based on a permanent vacuum chamber
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M. Renkens, P.H.J. Schellekens (2)
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STC P, 42/1/1993, P.581
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Keywords: Interference Refractometer, Laser Interferometry, Refractive Index |
Abstract : A new accurate interference refractometer, without pumping device, has
been developed. The refractometer is based on a commercially available
laser measurement system and uses a prismatic measuring cell, containing
a permanent vacuum chamber. Measurements of the refractive index of air
can be carried out accurately, easily and quickly with this instrument.
l'or this instrument also a new arrangement of a double pass, plane
mirror interferometer with high stability was developed. The accuracy of
the interference refractometer is analytically and experimentally
determined and appeared to be better as 1 part in 10^7 .
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Non-Contact probe for continuous measurement of surface inclination and position using dynamic irradiation of light beam
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K. Yamazaki (2), H. Aoyama, K.S. Lee, M. Sawabe
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STC P, 42/1/1993, P.585
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Keywords: Dimensional Measurement, Optical Measuring Instruments, Scanning |
Abstract : The paper deals with a development of a new non-contact probe module for
the high speed measurement of dimensions of a product. The probe module
can continuously and simultaneously detect a position and a surface
normal vector with custom signal processing algorithm developed. A probe
module using multiple optical fibers was designed and a simulation was
performed for verifying the proposed idea. A probe module was also
prototyped and tested. Successful results were obtained and its
performance coincided with the simulation. For practical application, a
multi-beam dynamic irradiation probe using the developed module was
designed and prototyped.
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Vibroscanning method for mondestructive measurement of small holes
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T. Masuzawa (2), Y. Hamasaki, M. Fujino
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STC P, 42/1/1993, P.589
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Keywords: Micromachining, Measuring Instruments |
Abstract : A new method for measuring inner dimensions of small holes was
developed. The electrical contact between a vibrating feeler and the
inner surface of a hole is detected, and the duty cycle of the contact
is measured. Through a controlled scan by a feeler with a constant duty
cycle, data on the ups and downs of the surface profile are obtained.
Through the application of this principle, a Ø 200 ?m hole with the
depth of 700 ?rn was successfully measured, and geometrical data such as
straightness, declination and taper were obtained.
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Four point method of roundness and spindle error measurements
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G.X. Zhang (1), R.K. Wang
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STC P, 42/1/1993, P.593
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Keywords: Precision, Measurements, Roundness |
Abstract : A new method of roundness and spindle error motion measurement is
presented in this paper. Roundness error of the workpiece and radial
error motion of the spindle are measured simultaneously by using 4
probes mounted with certain angle arrangement. This method gives high
accuracy for all harmonics which is difficult for three point method.
Based on error analysis a methodology for selecting optimal parameters
is given. Both computer simulation and experiment justify the high
accuracy of proposed method.
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Six axis of sensitivity force sensor for robots
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G. Ricciardi (2), L. Borsati
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STC P, 42/1/1993, P.597
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|
Keywords: Robot Assembly, Laser Beam Welding |
Abstract : The paper will present a force/moment sensor for robot advanced
applications (e.g. intelligent assembly, finishing, etc).
The main features are the very high linearity and repeatability, the
very simple procedure of calibration and the low cost of realization.
This is due to an innovative conception of geometry, design and
technology (laser welding).
The paper describes designing and realization techniques including the
problems relating to the laser welding of the two pieces that form the
sensor and presents the design specifications.
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A six degrees of freedom fine motion mask stage for X-ray aligner
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N. Kikuiri, N. Uchida, O. Kuwabara / H. Makino (1)
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STC P, 42/1/1993, P.603
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|
Keywords: Precision, Nanotechnology, Alignment |
Abstract : A fine motion mechanism has been developed for an x-ray aligner. The
mechanism to align a mask and a wafer precisely has to move with a
nanometer-order resolution for several hundred micrometers, which is
impossible to achieve with piezoelectric actuators. The mechanism is
driven by servomotors, and their displacements are reduced by wedges and
ball screws. To obtain high resolution, these transmission parts are
designed not to have hysteresis. A better than 20 nm resolution in
feedback control with an encoder and a better than 2.5 nm resolution in
feedback control using a capacitance micrometer have been achieved.
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Magnetic bearing stage for photolithography
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M.E. Williams, D.L. Trumper, R. Hocken (1)
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STC P, 42/1/1993, P.607
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Keywords: Mechatronics, Precision, Methodology |
Abstract : This paper describes a linear magnetic nearing stage which controls a
suspended object in six degrees of freedom. The intended applications is
for X-Y wafer positioning in photolithography stages. Magnetic bearings
offer superior performance and resolution over existing mechanical X-Y
stages. An advanced prototype magnetic bearing stage that improves the
ideas verified in the existing stage has been designed and is currently
under consideration. The paper will also present the advanced stage
design methodology used and the reasons for the decisions made.
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Generation of sculptured surfaces by means of an ultra-precision milling machine
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Y. Takeuchi (2), K. Ato, S. Kawakita, K. Sawada, T. Sata (1)
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STC P, 42/1/1993, P.611
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|
Keywords: Ultra-Precision, Milling Machine, Sculptured Surface |
Abstract : The study deals with the development of an ultraprecision milling
machine, which allows the production of workpieces with sculptured
surfaces. Until now, a variety of precision parts have been produced by
ultra-precision diamond turning machines. However, they can not cope
with making sculptured surfaces, which have higher requirements. The
ultra-precision milling machine developed consists of an air spindle
with a milling tool and a three-axis feed mechanism. As a milling tool,
a pseudo ball-endmill is designed by slightly offsetting a conventional
diamond tool having a nose radius. It is found that the ultra-precision
milling machine can produce workpieces with sculptured surface in
surface roughness of 70 nm Rmax.
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From unambiguousty defined geometry to the perfect quality control loop
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A. Wirtz (1), C. Gächter, D. Wipf
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STC P, 42/1/1993, P.615
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Keywords: Precision, Metrology, NC-Programming |
Abstract : At the CIRP General Assembly 1986 Vectorial Tolerancing, a model for a
quality control loop with a real three dimensional correction was
presented [4]. In the fifties we learned how to control an automatic
lathe by statistical quality control We were successful, because there
are only one dimensional features [1]. In this case the calculated
deviations could be used directly as a correcting value. In the milling
process each feature of a geometric element, like the position and the
direction requires up to two correcting procedures. Now such a quality
control loop has been successfully built. On the basis of vectorial
defined workpiece geometry and the machine kinematics, the NC data for a
five axis milling machine and a co-ordinate measuring machine is being
produced. After manufacturing the workpiece, the actual geometry is
measured, and from it the correction values are calculated. The
regulation of the workpiece geometry results from the feedback of the
correction values into the planning process.
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Comparison of combinatorial rules for machine error budgets
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Y.L. Shen, N.A. Duffie (2)
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STC P, 42/1/1993, P.619
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Keywords: Accuracy, Errors, Budgeting, Uncertainty, Design, Machine Tools, Coordinate Measuring Machines (CMM) |
Abstract : An error budget is an analysis tool for the prediction and control of
the total error of a machine system for which accuracy is an important
measurement of performance. The error budget concept is commonly applied
in designing precision machine tools and precision measuring machines
and requires application of a combinatorial rule to assess total error
which is contributed to by a number of individual error components. No
single generally agreed upon combinational rule exists for predicting
maximum total error that may result from many error components, and
precision machine designers often apply empirical formula rules that
have evolved from practical experience.
Combinatorial rules based on the central limit theorem (CLT) in
probability theory and the uncertainty interval concept are described in
this paper and compared to two empirical formula rules using two
precision machine error source examples reported in the literature. It
is shown using Monte Carlo simulations that the CLT combinatorial rules
and the empirical formulas adequately predict maximum total errors.
However, the CLT rules provide a more rigorous methodology than an
empirical formula for predicting total error. Moreover, a confidence
level associated with the estimated total errors can be specified for
error budgeting in precision machine design.
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STC S |
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Photothermal sensing techniques for measuring material properties and near-surface defects
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|
G. Goch, B. Schmitz, M. Reick / R. Hocken (1)
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|
STC S, 42/1/1993, P.623
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|
Keywords: Surface Properties, Coatings, Defects |
Abstract : Photothermal measurement techniques, particularly the optical beam
deflection (Mirage effect) and the photothermal radiometry, are able to
determine optical and thermal properties of bulk materials, surfaces and
coatings in a non-contact and non-destructive manner. Special interest
is focused on the non-destructive parameter evaluation of coatings, of
disturbed zones and surface layers after manufacturing processes (e.g.
grinding, hardening) and on material inspections (e.g. Vickers test).
This paper presents a few recent results of the photothermal beam
deflection technique to characterize the optical and thermal properties
of bulk solids, of surfaces and subsurface hidden structures. The use of
the photothermal technique to determine the thickness of coatings will
be illustrated exemplarily. The thermal diffusivity, which influences
decisively the heat transfer in non-stationary processes (e.g.
cutting,), was measured on non-transparent bulk materials. Furthermore,
a model for the change of material properties after manufacturing steps
and testing procedures was investigated. A short comprehensive survey of
both theoretical and experimental aspects of the photothermal effect for
microscopic imaging and related phenomena will be given.
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Material characterization of a machined surface using an anisotropic acoustic Lens
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|
T. Semba, Y. Tani, H. Sato (1)
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STC S, 42/1/1993, P.627
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|
Keywords: Surfaces, Acoustic Microscopes, Nondestructive Tests |
Abstract : Metallurgical orientation generated by plastic sliding on the cutting
edge produces material anisotropy in both the cutting direction, and the
feeding direction on a machined surface. This paper reports on
experimental research conducted to evaluate the material anisotropy on a
machined surface by means of a scanning acoustic microscope. A
point-focus anisotropic lens that can be used for observing an acoustic
image and evaluating an acoustic material signature was developed. Then,
material characterization on the end milled surface was carried out. It
was revealed that the Rayleigh wave velocity, measured while rotating
the anisotropic lens, showed a periodical change having peak values in
the cutting direction and the feeding direction. At the same time, it
became clear that the degree of material anisotropy, the angle of
metallurgical orientation and the mean Young's modulus could he
evaluated separately through analysis of the measured Rayleigh vane
velocity.
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A study of chip surface characteristics during the machining of steel
|
|
V.C. Ventakesh (1), D.Q. Zhou, D.T. Quinto, W. Xue
|
|
STC S, 42/1/1993, P.631
|
|
Keywords: Surface Properties, Coating, Oxides |
Abstract : Carbide inserts of different geometry (SMG, CNMG, CNMG-MG, CPMP, and
SPMP) with a variety of coatings CVD TiN, PVD TiN, CVD (TiCN/TiC/A1_2
0_3 ), CVD (TiCN/TiC) + PVD TiN, CVD TiC, and TiN/ A1_2 0_3 ,..TiCN]
were used to machine AISI 1018 steel at different speeds with and
without a coolant. Three typical colors deep blue, blue, and golden
brown were analyzed and found to contain varying amounts of oxide layers
consisting of FeO, Fe_2 0_3 , and Fe_3 0_4 . Chip roots from
turning/drilling operations were studied for secondary shear/built-up
edge formation, and temperatures calculated and related to chip color.
Chip color classification, brightness, surface roughness, waviness,
roundness, and chip strain were measured and evaluated.
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Characterization of surface texture generated by plateau honing process
|
|
M.C. Malburg, J. Raja / D.J. Whitehouse (1)
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STC S, 42/1/1993, P.637
|
|
Keywords: Surfaces, Honing |
Abstract : The plateau honing operation is being widely used for finishing of
cylinder liners for internal combustion engines. Plateau honing has been
shown to significantly reduce the costly running-in period due to the
fact that very little further modification of the texture is required
once the liner is put into operation. In order to better understand,
control, and ultimately "engineer" plateau honed surfaces, a
comprehensive means of characterizing this texture is required. In this
paper the techniques currently used are briefly reviewed and an
alternate approach is proposed. The proposed approach is based on
analyzing the cumulative distribution plot on a normal probability graph.
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Manufacture to function - in optics
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|
D.J. Whitehouse (1)
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STC S, 42/1/1993, P.641
|
|
Keywords: Surfaces, Optics |
Abstract : Surface texture can be used to monitor the manufacturing process. The
surface of a component is also important in determine how well the
component performs. Ideally, the manufacturing process should be picked
to ensure that the part work satisfactorily. In this paper, as an
example, the specific function of gloss is chosen as a requirement. It
is shown what sort of surface is most suitable for this, and how this
surface should be made, thereby completing the chain from manufacture to
function.
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Nano-topography of ultra-precise ground surface of fine ceramics using atomic force microscope
|
|
Y. Tchida, K. Kishi / H. Sato (1)
|
|
STC S, 42/1/1993, P.647
|
|
Keywords: Grinding, Ultra-Precision, Ceramics |
Abstract : The nanometer scale imaging of ultra-precise around surface of Si_3 N_4
ceramics has been conducted with an atomic force microscope. An
ultra-precise surface with a roughness of about 8 nm Rmax could be
generated when fine grain diamond wheel with a grain size of #10.000 was
used. The topography of the ultra-precise ground surface is affected by
the protrusion of grain boundary phase out of Si_3 N_4 crystal surface
as well as by the unevenness of grinding streaks. There is an infinite
number of surface. These ultra-fine projections have slightly an
anisotropic geometry in the shape and in the distribution.
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