- Email: [email protected]
31st CIRP general assembly
r
Ball brochure Selection of ball materials for conditions of service requiring resistance to corrosion, abrasion, extremes of temperature and other factors, is claimed to be aided by a brochure from Insley. Balls down to A F B M A Grade 5 and DIN Class I (Super Precision) and in ~pecial materials (eg titanium carbide, silicon carbide, polycarbonate resin, acetal resin, tantalum, Carpenter 20Cb-3 and M-50 high speed steel) can be supplied. Insley Industrial Ltd, Precision Ball Division, PO Box 12, Eastern Road, Bracknell, Berkshire, UK, RG12 1LT
Manufacturing systems The Society of Manufacturing Engineers (SME) has announced "The Journal of Manufacturing Systems' which will be published early this year. The specific goals of this journal are: to publish relevant literature for manufacturing industries, research and development organizations and the SME membership on the underlying theory and application methodologies of integrating manufacturing processes into systems; to encourage the dissemination of scientific meth-
ods to plant operating personnel on systems concepts with the potential of decreasing manufacturing costs, increasing productivity and assuring product quality; and to provide a forum for the researcher and practitioner to express views on current and future directions of manufactu ring systems research, development and implementation. The editor will be Professor J. G. Bollinger of the University of Wisconsin. Appointments to the Editorial Executive Committee include Professor M. M. Barash of Purdue University; Dr M. E. Merchant of Cincinnati Milacron, Inc and Professor J. Peklenik of the University of Ljubljana, Yugoslavia, who will also serve as Associate Editors. SME, One SME Drive, PO Box 930, Dearborn, MI 48128, USA
Quality assurance BSI has just published "Quality Assurance", the BSI Handbook 22, which is a compilation of seven standards: (i) terminology standards which set down agreed terms and definitions in current quality assurance practice: BS4778 "Glossary of terms used in quality assurance (including reliability and
maintainability terms)" and BS5233 "Glossary of terms used in metroIogy"; (ii) basic or generic standards written in the form of guides (not involving contractual requirements): BS4891 " A guide to quality assurance", BS5670 "Guide to the reliability of systems, equipments and components" and BS6143 "Guide to the determination and use of quality related costs"; and definitive system specifications (with guides) for use in contractual situations: BS5750 "Quality systems" and BS5781 "Measurement and calibration systems". The Handbook should be of value to directors and senior managers in marketing oriented industries where quality and quality assurance are dictated largely by considerations of cost and competitiveness; to purchasers and manufacturers of products and systems that are governed by agreed contractual commitments; to third party quality assurance assessment schemes; and as a practical reference book for use in education. This Handbook is available from BSI Sales Department, Newton House, 195 Pentonville Road, London, UK, N1 9ND. Price: £75 (BSI subscribing members £37.50)
Conference report 31 August-2 September 1981, Toronto, Canada
31st CIRP GeneralAssembly If one of the stimuli for focussing increased attention on precision engineering is the desire to increase automation and replace fitting with assembly, then every precision engineer should balance his technical efforts with an interest in the social, political and economic factors affecting the rate of automation. Professor Matthias' opening remarks at the public session of the 31st CI RP General Assembly certainly provided plenty of food for thought. Historically, productivity has always increased with increasing production. According to Matthias, however, "The Western world is already saturated with consumer products and cannot absorb any more"; in addition,
PRECISION ENGINEERING
increasing industrialisation in the less developed nations will not only continue to erode export markets but will provide increasing competition in the domestic markets of the developed nations. Productivity is certain to remain the 'order-of-merit' and the move towards the computer integrated automatic factory seems inexorable. Such automation which reduces costs and increases productivity seems inevitable. It will reduce the number of jobs in manufacturing industry, but create a demand for workers with a new profile of skills. Will we have the foresight to ensure an adequate supply of suitably skilled staff? Will produc-
tion runs inevitably increase, bringing the concomitant reduction in consumer choice? If the questions mirror many that were posed at the roundtable discussion in Davos, the message is clear. Engineers must be prepared to accept their share of the challenge in finding answers or, if they default, not to demur at the decisions of accountants, economists and the like. Again in the public session, Yon Turkovich 1 considered mechanical and metallurgical properties of the workpiece as part of a property response matrix analysis "to address the magnificently complex problem" of materials behaviour in machining. In emphasising the need to consider the surfaces produced, he also produced
51
I
I tTT"
,' ~vrrI
',Trrl
the eminently quotable comment: '~Ne don't do all this cutting just to produce chips .... except in universities". Metrology In the first of two papers on coordinate measuring machines, Clement 2 presented a model of machine movements in a curvilinear coordinate system based on the hypothesis that errors are predominantly systematic. The system of curved coordinates can be deduced from theoretical rectangular coordinates issuing a displacement field and associated deformation tensor. Experimental determination of the tensor was outlined and three coefficients to characterise machine quality proposed. Beyer and Kunzmann's discussion3 of the practical problems of checking measuring machines demonstrated that the results obtained are strongly influenced by the test method adopted and that test procedures must be optimised. Indeed their main conclusions were that it is impossible to calibrate, in the normal metrological meaning of the word, coordinate measuring machines and that comparisons of test results are meaningless tJnless the details of the test method are known. Murthy and Rao4 described a method for evaluating cylindricity which is analogous to routinely used flatness evaluations. While the mathematical analysis was not questioned, a shadow was cast over the whole presentation when it transpired that the experimental results reported in the paper were obtained using a standard Talyrond which does not have an adequate straight edge to allow the datum to be moved vertically. Thermal expansion of the tool is one of the main causes of cylindricity, or taper, errors in turning. The paper by Sata et al s described a compensating technique for nc lathes based on a model of expansion as a function of cutting conditions. Experimental results quoted show an improvement in workpiece accuracy by a factor of more than five. A programme to determine the density of pure water at the National Research Laboratory of Metrology in
52
Japan demands geometrically simple sinking objects where the volume is known to about 1 ppm. Quartz spheres seem to offer an optimum approach and Goto e described a method of evaluating departures from a mean sphere. In industrial purchasing of threaded fasteners, acceptance of statistical inspection by the supplier implies acceptance of about 2% faulty parts. With manual assembly operations, this does not normally create significant problems. If assembly is automated, however, average cycle times of the order of 1 0 - 3 0 s lead by definition to several line stoppages per hour. In this type of application, therefore, 100% inspection should prove cost effective. Warnecke et al 7 described a prototype system for checking threaded components which uses a line scan camera and a silhouette of the workpiece. The authors note that significant reductions in the measurement uncertainty could be achieved, at a price, by using two diode cameras. One of the major barriers to the wide-spread application of adaptive control in machining is the availability of suitably robust and accurate transducers. Novak a described an elegant electro-optic device which can be used in process to indicate diameter, out of roundness and vibration. The measuring range is 280 mm with resolution and repeatability quoted as 1 #m and 3/~m respectively. The commercial potential, however, of a system incorporating a HeNe laser, six penta-prisms and two corner cubes remains to be proven. Surfaces Stylus profilometry has long been synonymous with advances in surface characterisation, but speed of operation and lack of robustness have proved major obstacles in production environments. To many, optical techniques seem to provide a solution although, as Teague and Vorburger pointed out in a recent review (Optical Techniques for On-Line Measurement of Surface Topography. Precision Engineering, 1981, 3, 61-83), the majority of these techniques have to be considered merely as comparators. Some such systems are in use in indus-
try although, in some cases, performance has not been satisfactory. In the keynote paper for the Surfaces session, Teague, Vorburger and Maystre presented a clear demonstration of the sources of this dissatisfaction. First, it appears that most industrial users are not aware of the coupling between height and wavelength in the output of light scattering instruments and have insufficient understanding of the problem. More fundamentally, however, they showed that, even when simple sinusoidal surfaces are chosen, there are large areas of a slope-relative wavelength space occupied by manufactured surfaces for which there is no valid theory and that there are large regions for which current measurement techniques are not based on adequate theory. Sato and O-Hori ]° described an elegant, tv camera-based light sectioning microscope system with a horizontal resolution quoted as 3 #m. Using perspective views, contour maps and two dimensional Fourier analysis, the authors indicate that the system can be used in the study of self-excited chatter, tool motions, regenerative effects and surface wave forms. The purpose of Pandit's paper 11 was to demonstrate that Data Dependent Systems of modelling and characterisation can provide a detailed estimate of wavelength composition and correlation. Examples of the characteristic shapes, wavelength decomposition and their relation to machining processes are given for edm, turning and grinding. Taniguchi 12 described experimental work in ion beam sputter etching of cemented tungsten carbide; the effects of ion incident angle, energy and ion species on surface roughness were strident. The conclusion drawn is that, with optimum machining parameters, the process could be used for fine adjustment of the dimensions of block gauges and other highly precise mechanical components. Nee and Venkatesh 13 outlined a study of the ballizing process in which precision ground tungsten carbide balls of a prescribed diameter are forced through slightly undersized bores. It appears that interference must be opti-
J A N 1982 V O L 4 NO 1
I'
mised t o give the greatest possible i m p r o v e m e n t in bore surface finish and that an oversized ball has to be used to obtain a specified final diameter. The a m o u n t of oversize can be estimated f r o m the recovery angle. Improvements in surface finish by a factor of 10 and in roundness by a factor of 2 to 5 were reported.
Physical and chemical machining A p p l i c a t i o n of new techniques such as electron beam and X-ray lithography in the production of very large scale integrated circuits places severe demands on the finish and flatness of silicon wafers. It appears that damage free surfaces w i t h roughness of the order of 10--20 A and flatness t o 3- 5 / J m over 125 m m cannot be produced using conventional polishing systems. Watanabe 14 described a polishing machine based on a taper land thrust bearing in which six wafers in planetary m o t i o n are polished simultaneously by the erosive action of abrasive particles in a hydrodynamic f i l m . Results obtained include flatness t o 0.3/J,m over 70 m m and 10 A roughness. According t o Shpitalni is , industrial use of electro~chemical grinding has been severely limited by the lack of accuracy obtainable, and specifically by overcut. He described an adaptive control strategy, based on feed rate, which is claimed t o give substantial improvements in overcut. Chen et a116 outlined w o r k on the electrochemical honing of gears. They indicate that it is a more productive gear finishing process than grinding, involving l o w forces, hence avoiding rigidity constraints, and eliminates vibration and balance problems. Other papers in the session considered the effects of carbon content and microstructure in ecm of steel 16 and the relationship between copying accuracy and electrolyte used in ecm of t i t a n i u m alloys.
Iogy and Abrasive Processes clashed leaving this reviewer at least ten papers 18-27 to read in the Annals* on the flight home. The most obviously relevant of these is Hahn's discussion ~ of threshold forces and their influence on size, roundness and f o r m in precision grinding. In the Machine Tools session, Peters et al 2s reported on the performance of high damping metallic materials in additive damping treatments. French and Vraets 29 outlined a simple control system for maximising the o u t p u t torque of stepper motors which appears suitable f o r high speed positioning systems. C. Evans
References* 1.
Von Turkovich B.F., Field M. and Konig W. Survey on Materials Beha-
viour in Machining 2.
Clement A. and Bourdat P. Commande
Adaptive Dimensionelle d'une Machine Mesurer Tridimensionelle 3.
Bayer W. and Kunzmann H. Verfleichende Betrachtungen ~iber Messger§te und Massverk6rperungen f~r die Pr6fung von MehrkoordinatenMessger§ten
4.
Murthy T.S.R. and Rao S.H. A Simple Approach for Evaluation of Cylindrical Surfaces
5.
Sata T., Takeuchi Y., Sakamoto M. and
12. Taniguchi N. and Miyamoto I. Surface Finishing of Cemented Tungsten Carbide Chip due to Ion Beam Sputter Etching 13. Nee A.Y.C. and Vankatash V.C. A Study of the Ballizing Process 14. WatanabeJ. and Suzuki J. High Precision Polishing of Semi-Conductor Materials Using Hydrodynamic Principle 15. Shpitalni M., Koran Y. and Lanz E.
Adaptive Control System for Optimizing the ECG Process under the Overcut Constraint 16. Fukunaga H. and Maruyama M. Effects of Carbon Content and Micro-structures on the Current Efficiency in Case of Electro-Chemical Machining of Fe-C Alloys 17. Yu C.Y., Yang Y.S. and Chang C.K. The Relation Between the Copying Accuracy and Electrolytes of Electrochemical Machining for Titanium Alloys 18. Sexton J.S. and Stone B.J. The Development of an Ultrahard Abrasive Grinding Wheel which Suppresses Chatter 19. Salje E. and Damlos H.H. Problems in Profile Grinding - Angular Plunge Grinding and Surface Grinding 20. Malkin S. Grinding Cycle Optimization 21.
Hagiuda Y., Karikoma K. and Nakagawa T. Manufacturing of a Sintered Cast Iron Lapping Plate with Fixed Abrasives and its Lapping Abilities
Weck M. Improvement of Working Accuracy on NC Lathe by Compensation for the Thermal Expansion of Tool
22. Matsuo T. and Okamura K. Wear Characteristic of General and Superhard Abrasive Grains Against Various Hard Materials
6.
lizuka K. and Goto M. Evaluation of Sphericity for Determining Volume of Spheres in the Highest Accuracy
23. Dorin A.C. and Marinascu I.D. The Establishment of the Cutting of the Diamond Wheels in the Plane Grinding
7.
Warnacke H.J., Pavel G. end Kuhn G.
Optical Testing of Bolt Type Screws
24. Tanaka T. Affinity of Diamond for Metals
8.
Novak A. Sensing of Workpiece Diameter, Vibration, and Out-of-Roundness by Laser. Way to Automate Quality Control
25. Bhataja C.P. The Importance of Abrasive Grinding Wheel Hardness Control for Productivity of Production Grinding Operations
9.
Teagua E.C., Vorburgar T.V. and Maystre D. Light Scattering from
26. Hahn R.S. The Influence of Threshold Forces on Size, Roundness and Contour Errors in Precision Grinding
Manufactured Surfaces 10. Sato H. and O-Hori M. Characteristics of Two Dimensional Surface Roughness. Taking Self-Excited Chatter Marks as Objective
27.
28.
Comments
11, Pandit S.M. Characteristic Shapes and Wavelength Decomposition of Surfaces in Machining
As ever, parallel sessions posed the major problem of deciding which session to attend. For example, Metro-
*ClRP Annals, Volume 30 (1981) is published by Hallwag Verlag, Nordring 4, CH-3001, Bern, Switzerland
PRECISION ENGINEERING
J'
Vinh T., Aouichi A. and Blouet J.
About Non Stationary Signal Processing. Applications to the Study of Evolutive Solid Friction Experiments Peters J., Snoeys R. and Vandeurzen U.
Additive Damping Treatment for Mechanical Structures 29. French D. and Vraets W.J. Minor Closed Loop Control of a Single-Stack Variable Reluctance Stepping Motor for High Speed Positioning
53
Ball brochure Selection of ball materials for conditions of service requiring resistance to corrosion, abrasion, extremes of temperature and other factors, is claimed to be aided by a brochure from Insley. Balls down to A F B M A Grade 5 and DIN Class I (Super Precision) and in ~pecial materials (eg titanium carbide, silicon carbide, polycarbonate resin, acetal resin, tantalum, Carpenter 20Cb-3 and M-50 high speed steel) can be supplied. Insley Industrial Ltd, Precision Ball Division, PO Box 12, Eastern Road, Bracknell, Berkshire, UK, RG12 1LT
Manufacturing systems The Society of Manufacturing Engineers (SME) has announced "The Journal of Manufacturing Systems' which will be published early this year. The specific goals of this journal are: to publish relevant literature for manufacturing industries, research and development organizations and the SME membership on the underlying theory and application methodologies of integrating manufacturing processes into systems; to encourage the dissemination of scientific meth-
ods to plant operating personnel on systems concepts with the potential of decreasing manufacturing costs, increasing productivity and assuring product quality; and to provide a forum for the researcher and practitioner to express views on current and future directions of manufactu ring systems research, development and implementation. The editor will be Professor J. G. Bollinger of the University of Wisconsin. Appointments to the Editorial Executive Committee include Professor M. M. Barash of Purdue University; Dr M. E. Merchant of Cincinnati Milacron, Inc and Professor J. Peklenik of the University of Ljubljana, Yugoslavia, who will also serve as Associate Editors. SME, One SME Drive, PO Box 930, Dearborn, MI 48128, USA
Quality assurance BSI has just published "Quality Assurance", the BSI Handbook 22, which is a compilation of seven standards: (i) terminology standards which set down agreed terms and definitions in current quality assurance practice: BS4778 "Glossary of terms used in quality assurance (including reliability and
maintainability terms)" and BS5233 "Glossary of terms used in metroIogy"; (ii) basic or generic standards written in the form of guides (not involving contractual requirements): BS4891 " A guide to quality assurance", BS5670 "Guide to the reliability of systems, equipments and components" and BS6143 "Guide to the determination and use of quality related costs"; and definitive system specifications (with guides) for use in contractual situations: BS5750 "Quality systems" and BS5781 "Measurement and calibration systems". The Handbook should be of value to directors and senior managers in marketing oriented industries where quality and quality assurance are dictated largely by considerations of cost and competitiveness; to purchasers and manufacturers of products and systems that are governed by agreed contractual commitments; to third party quality assurance assessment schemes; and as a practical reference book for use in education. This Handbook is available from BSI Sales Department, Newton House, 195 Pentonville Road, London, UK, N1 9ND. Price: £75 (BSI subscribing members £37.50)
Conference report 31 August-2 September 1981, Toronto, Canada
31st CIRP GeneralAssembly If one of the stimuli for focussing increased attention on precision engineering is the desire to increase automation and replace fitting with assembly, then every precision engineer should balance his technical efforts with an interest in the social, political and economic factors affecting the rate of automation. Professor Matthias' opening remarks at the public session of the 31st CI RP General Assembly certainly provided plenty of food for thought. Historically, productivity has always increased with increasing production. According to Matthias, however, "The Western world is already saturated with consumer products and cannot absorb any more"; in addition,
PRECISION ENGINEERING
increasing industrialisation in the less developed nations will not only continue to erode export markets but will provide increasing competition in the domestic markets of the developed nations. Productivity is certain to remain the 'order-of-merit' and the move towards the computer integrated automatic factory seems inexorable. Such automation which reduces costs and increases productivity seems inevitable. It will reduce the number of jobs in manufacturing industry, but create a demand for workers with a new profile of skills. Will we have the foresight to ensure an adequate supply of suitably skilled staff? Will produc-
tion runs inevitably increase, bringing the concomitant reduction in consumer choice? If the questions mirror many that were posed at the roundtable discussion in Davos, the message is clear. Engineers must be prepared to accept their share of the challenge in finding answers or, if they default, not to demur at the decisions of accountants, economists and the like. Again in the public session, Yon Turkovich 1 considered mechanical and metallurgical properties of the workpiece as part of a property response matrix analysis "to address the magnificently complex problem" of materials behaviour in machining. In emphasising the need to consider the surfaces produced, he also produced
51
I
I tTT"
,' ~vrrI
',Trrl
the eminently quotable comment: '~Ne don't do all this cutting just to produce chips .... except in universities". Metrology In the first of two papers on coordinate measuring machines, Clement 2 presented a model of machine movements in a curvilinear coordinate system based on the hypothesis that errors are predominantly systematic. The system of curved coordinates can be deduced from theoretical rectangular coordinates issuing a displacement field and associated deformation tensor. Experimental determination of the tensor was outlined and three coefficients to characterise machine quality proposed. Beyer and Kunzmann's discussion3 of the practical problems of checking measuring machines demonstrated that the results obtained are strongly influenced by the test method adopted and that test procedures must be optimised. Indeed their main conclusions were that it is impossible to calibrate, in the normal metrological meaning of the word, coordinate measuring machines and that comparisons of test results are meaningless tJnless the details of the test method are known. Murthy and Rao4 described a method for evaluating cylindricity which is analogous to routinely used flatness evaluations. While the mathematical analysis was not questioned, a shadow was cast over the whole presentation when it transpired that the experimental results reported in the paper were obtained using a standard Talyrond which does not have an adequate straight edge to allow the datum to be moved vertically. Thermal expansion of the tool is one of the main causes of cylindricity, or taper, errors in turning. The paper by Sata et al s described a compensating technique for nc lathes based on a model of expansion as a function of cutting conditions. Experimental results quoted show an improvement in workpiece accuracy by a factor of more than five. A programme to determine the density of pure water at the National Research Laboratory of Metrology in
52
Japan demands geometrically simple sinking objects where the volume is known to about 1 ppm. Quartz spheres seem to offer an optimum approach and Goto e described a method of evaluating departures from a mean sphere. In industrial purchasing of threaded fasteners, acceptance of statistical inspection by the supplier implies acceptance of about 2% faulty parts. With manual assembly operations, this does not normally create significant problems. If assembly is automated, however, average cycle times of the order of 1 0 - 3 0 s lead by definition to several line stoppages per hour. In this type of application, therefore, 100% inspection should prove cost effective. Warnecke et al 7 described a prototype system for checking threaded components which uses a line scan camera and a silhouette of the workpiece. The authors note that significant reductions in the measurement uncertainty could be achieved, at a price, by using two diode cameras. One of the major barriers to the wide-spread application of adaptive control in machining is the availability of suitably robust and accurate transducers. Novak a described an elegant electro-optic device which can be used in process to indicate diameter, out of roundness and vibration. The measuring range is 280 mm with resolution and repeatability quoted as 1 #m and 3/~m respectively. The commercial potential, however, of a system incorporating a HeNe laser, six penta-prisms and two corner cubes remains to be proven. Surfaces Stylus profilometry has long been synonymous with advances in surface characterisation, but speed of operation and lack of robustness have proved major obstacles in production environments. To many, optical techniques seem to provide a solution although, as Teague and Vorburger pointed out in a recent review (Optical Techniques for On-Line Measurement of Surface Topography. Precision Engineering, 1981, 3, 61-83), the majority of these techniques have to be considered merely as comparators. Some such systems are in use in indus-
try although, in some cases, performance has not been satisfactory. In the keynote paper for the Surfaces session, Teague, Vorburger and Maystre presented a clear demonstration of the sources of this dissatisfaction. First, it appears that most industrial users are not aware of the coupling between height and wavelength in the output of light scattering instruments and have insufficient understanding of the problem. More fundamentally, however, they showed that, even when simple sinusoidal surfaces are chosen, there are large areas of a slope-relative wavelength space occupied by manufactured surfaces for which there is no valid theory and that there are large regions for which current measurement techniques are not based on adequate theory. Sato and O-Hori ]° described an elegant, tv camera-based light sectioning microscope system with a horizontal resolution quoted as 3 #m. Using perspective views, contour maps and two dimensional Fourier analysis, the authors indicate that the system can be used in the study of self-excited chatter, tool motions, regenerative effects and surface wave forms. The purpose of Pandit's paper 11 was to demonstrate that Data Dependent Systems of modelling and characterisation can provide a detailed estimate of wavelength composition and correlation. Examples of the characteristic shapes, wavelength decomposition and their relation to machining processes are given for edm, turning and grinding. Taniguchi 12 described experimental work in ion beam sputter etching of cemented tungsten carbide; the effects of ion incident angle, energy and ion species on surface roughness were strident. The conclusion drawn is that, with optimum machining parameters, the process could be used for fine adjustment of the dimensions of block gauges and other highly precise mechanical components. Nee and Venkatesh 13 outlined a study of the ballizing process in which precision ground tungsten carbide balls of a prescribed diameter are forced through slightly undersized bores. It appears that interference must be opti-
J A N 1982 V O L 4 NO 1
I'
mised t o give the greatest possible i m p r o v e m e n t in bore surface finish and that an oversized ball has to be used to obtain a specified final diameter. The a m o u n t of oversize can be estimated f r o m the recovery angle. Improvements in surface finish by a factor of 10 and in roundness by a factor of 2 to 5 were reported.
Physical and chemical machining A p p l i c a t i o n of new techniques such as electron beam and X-ray lithography in the production of very large scale integrated circuits places severe demands on the finish and flatness of silicon wafers. It appears that damage free surfaces w i t h roughness of the order of 10--20 A and flatness t o 3- 5 / J m over 125 m m cannot be produced using conventional polishing systems. Watanabe 14 described a polishing machine based on a taper land thrust bearing in which six wafers in planetary m o t i o n are polished simultaneously by the erosive action of abrasive particles in a hydrodynamic f i l m . Results obtained include flatness t o 0.3/J,m over 70 m m and 10 A roughness. According t o Shpitalni is , industrial use of electro~chemical grinding has been severely limited by the lack of accuracy obtainable, and specifically by overcut. He described an adaptive control strategy, based on feed rate, which is claimed t o give substantial improvements in overcut. Chen et a116 outlined w o r k on the electrochemical honing of gears. They indicate that it is a more productive gear finishing process than grinding, involving l o w forces, hence avoiding rigidity constraints, and eliminates vibration and balance problems. Other papers in the session considered the effects of carbon content and microstructure in ecm of steel 16 and the relationship between copying accuracy and electrolyte used in ecm of t i t a n i u m alloys.
Iogy and Abrasive Processes clashed leaving this reviewer at least ten papers 18-27 to read in the Annals* on the flight home. The most obviously relevant of these is Hahn's discussion ~ of threshold forces and their influence on size, roundness and f o r m in precision grinding. In the Machine Tools session, Peters et al 2s reported on the performance of high damping metallic materials in additive damping treatments. French and Vraets 29 outlined a simple control system for maximising the o u t p u t torque of stepper motors which appears suitable f o r high speed positioning systems. C. Evans
References* 1.
Von Turkovich B.F., Field M. and Konig W. Survey on Materials Beha-
viour in Machining 2.
Clement A. and Bourdat P. Commande
Adaptive Dimensionelle d'une Machine Mesurer Tridimensionelle 3.
Bayer W. and Kunzmann H. Verfleichende Betrachtungen ~iber Messger§te und Massverk6rperungen f~r die Pr6fung von MehrkoordinatenMessger§ten
4.
Murthy T.S.R. and Rao S.H. A Simple Approach for Evaluation of Cylindrical Surfaces
5.
Sata T., Takeuchi Y., Sakamoto M. and
12. Taniguchi N. and Miyamoto I. Surface Finishing of Cemented Tungsten Carbide Chip due to Ion Beam Sputter Etching 13. Nee A.Y.C. and Vankatash V.C. A Study of the Ballizing Process 14. WatanabeJ. and Suzuki J. High Precision Polishing of Semi-Conductor Materials Using Hydrodynamic Principle 15. Shpitalni M., Koran Y. and Lanz E.
Adaptive Control System for Optimizing the ECG Process under the Overcut Constraint 16. Fukunaga H. and Maruyama M. Effects of Carbon Content and Micro-structures on the Current Efficiency in Case of Electro-Chemical Machining of Fe-C Alloys 17. Yu C.Y., Yang Y.S. and Chang C.K. The Relation Between the Copying Accuracy and Electrolytes of Electrochemical Machining for Titanium Alloys 18. Sexton J.S. and Stone B.J. The Development of an Ultrahard Abrasive Grinding Wheel which Suppresses Chatter 19. Salje E. and Damlos H.H. Problems in Profile Grinding - Angular Plunge Grinding and Surface Grinding 20. Malkin S. Grinding Cycle Optimization 21.
Hagiuda Y., Karikoma K. and Nakagawa T. Manufacturing of a Sintered Cast Iron Lapping Plate with Fixed Abrasives and its Lapping Abilities
Weck M. Improvement of Working Accuracy on NC Lathe by Compensation for the Thermal Expansion of Tool
22. Matsuo T. and Okamura K. Wear Characteristic of General and Superhard Abrasive Grains Against Various Hard Materials
6.
lizuka K. and Goto M. Evaluation of Sphericity for Determining Volume of Spheres in the Highest Accuracy
23. Dorin A.C. and Marinascu I.D. The Establishment of the Cutting of the Diamond Wheels in the Plane Grinding
7.
Warnacke H.J., Pavel G. end Kuhn G.
Optical Testing of Bolt Type Screws
24. Tanaka T. Affinity of Diamond for Metals
8.
Novak A. Sensing of Workpiece Diameter, Vibration, and Out-of-Roundness by Laser. Way to Automate Quality Control
25. Bhataja C.P. The Importance of Abrasive Grinding Wheel Hardness Control for Productivity of Production Grinding Operations
9.
Teagua E.C., Vorburgar T.V. and Maystre D. Light Scattering from
26. Hahn R.S. The Influence of Threshold Forces on Size, Roundness and Contour Errors in Precision Grinding
Manufactured Surfaces 10. Sato H. and O-Hori M. Characteristics of Two Dimensional Surface Roughness. Taking Self-Excited Chatter Marks as Objective
27.
28.
Comments
11, Pandit S.M. Characteristic Shapes and Wavelength Decomposition of Surfaces in Machining
As ever, parallel sessions posed the major problem of deciding which session to attend. For example, Metro-
*ClRP Annals, Volume 30 (1981) is published by Hallwag Verlag, Nordring 4, CH-3001, Bern, Switzerland
PRECISION ENGINEERING
J'
Vinh T., Aouichi A. and Blouet J.
About Non Stationary Signal Processing. Applications to the Study of Evolutive Solid Friction Experiments Peters J., Snoeys R. and Vandeurzen U.
Additive Damping Treatment for Mechanical Structures 29. French D. and Vraets W.J. Minor Closed Loop Control of a Single-Stack Variable Reluctance Stepping Motor for High Speed Positioning
53