Precision Manufacturing

Transcription

1 Precision Manufacturing

2 Precision Manufacturing David Dornfeld University of California at Berkeley Mechanical Engineering 6195 Etcheverry Hall Berkeley, California Dae-Eun Lee Lawrence Berkeley National Laboratory Mechanical Engineering 1 Cyclotron Road Berkeley, California 94720

3 David Dornfeld University of California at Berkeley Mechanical Engineering 6195 Etcheverry Hall Berkeley, California Dae-Eun Lee Lawrence Berkeley National Laboratory Mechanical Engineering 1 Cyclotron Road Berkeley, California Library of Congress Control Number: ISBN e-isbn Printed on acid-free paper Springer Science+Business Media, LLC All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now know or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights springer.com

4 To manufacturing engineers

5 TABLE OF CONTENTS Preface & Acknowledgements xvii I. Introduction to precision manufacturing Precision engineering Precision manufacturing Competitive drivers of precision manufacturing Historical developments in manufacturing Background Key drivers Historical examples Organization of this book 33 II. Machine design for precision manufacturing Background on machine design for manufacturing Philosophy of precision machine design Sources of error - overview 41 III. Principles of measurement Definition of terms accuracy, repeatibility, and resolution Accuracy Repeatability (or precision) Resolution Probabilistic measure of accuracy Metrology and measurement 57

6 viii PRECISION MANUFACTURING 3.3 Abbé s principle 3.4 Metrology techniques Measurement of dimension and angle Measurement of form Straightness Flatness Roundness Other form errors Measurement of surface roughness Kinematic precision Subsurface damage 112 IV. Mechanical errors Introduction Errors due to machine elements (excluding bearings) Kinematic design Connectivity Kinematic elements Contact and complex support Summary of kinematic design Structural compliance Microscale compliance Macroscale compliance Bearings and spindles Bearings Aerostatic bearings and spindles 163 V. Thermal errors Background on the thermal error problem Thermal effects in precision engineering Determining the effect of temperature other than 20 C Free and constrained bodies Effect of spatial temperature gradients Effect of temperature transients: soak-out time and sinusoidal response 187

7 TABLE OF CONTENTS ix 5.4 Conductive, convective, and radiative heat transfer parameters Specific heat sources and examples of thermal problems Environmental control of precision machinery Machine enclosures Factory and room enclosures Machine treatment without enclosures Thermal effects and metrology Observations 215 VI. Error mapping and error budgets Introduction Error mapping Error budget Definition of error budget Error budget flow chart Combinational rules for errors 234 VII. Error due to compliance and vibration Introduction Excitations in machine tools Weight deformation Cutting force deformation Type A deformation: Deformation due to the variation of the cutting force Introduction and background Examples for single edge cutting Machine stiffness and directional orientation Type B deformation: Deformation due to the variation of the stiffness along the tool path Comparison of the errors from deformation types A and B 7.5 Forced vibrations Self-excited vibrations (chatter) Introduction Basic stability; effect of structural dynamics 278

8 x PRECISION MANUFACTURING Variation of spindle speed and stability lobes Advanced analysis 292 VIII. Sensors for precision manufacturing Introduction The relevance of precision manufacturing and the need for in-process monitoring and control Requirements for sensor technology for precision manufacturing Overview of sensors in manufacturing Introduction Sensor systems for process monitoring New developments in signal and information processing for tool condition monitoring Introduction Intelligent sensors Implementation strategies Multisensor approaches Sensors for high speed machining Acoustic emission in manufacturing Background Acoustic emission sources-diagnostics Acoustic emission sources-process monitoring Acoustic emission in machining Signal processing, feature extraction and sensor fusion Introduction Intelligent sensor defined Sensor fusion defined Fusion methodologies Neural networks Applications of signal processing and sensor fusion Introduction Tool wear detection using time series analysis of acoustic emission 350

9 TABLE OF CONTENTS xi Time series analysis Experimental evaluation Sensor integration using neural networks for intelligent tool condition monitoring Use of multiple sensors Experimental evaluation The need for engineering models to design and predict the performance of in-process sensors Basic sensor classification and new sensing technologies Introduction Basic sensor types Mechanical sensors Thermal sensors Electrical sensors Magnetic sensors Radiant sensors Chemical sensors Applications of sensors in precision manufacturing AE-based monitoring of grinding wheel dressing Fast AE RMS analysis for wheel condition monitoring Grinding wheel topographical mapping Wheel wear mechanism AE-based monitoring of face milling AE-based monitoring of chemical mechanical planarization Monitoring of abrasive process parameters Precision scribing of CMP-treated wafers AE-based endpoint detection for CMP AE monitoring of surface chemical reactions for copper CMP 403

10 xii PRECISION MANUFACTURING AE characteristics of oxidation and dissolution in copper CMP Monitoring of precision scribing Monitoring of ultraprecision Turning of Single crystal copper Monitoring of ultraprecision turning of polycrystalline copper Summary 422 IX. Process planning for precision manufacturing Manufacturing system characteristics Process planning basics Process capability Background Process capability defined C p as a planning metric Legacy-system integration for precision manufacturing Future integration for precision manufacturing process planning 452 X. Precision machining processes Introduction Influence of machining parameters, work material, and tool geometry Influence of uncut chip thickness Machining brittle materials Effects of work material crystallography/ directionality Process operating conditions Precision mfg. processes-diamond turning/milling Introduction Machine tool design Tool design and alignment Chip formation and process mechanics Abrasive processes fixed and loose Fixed abrasive processes 505

11 TABLE OF CONTENTS xiii Material removal mechanisms Grinding forces, power and specific energy Grinding stiffness, contact stiffness and process time constant Nanogrinding Loose abrasive processes Polishing and lapping Chemical mechanical planarization (CMP) Process modeling in CMP Non-traditional processes 551 XI. Precision manufacturing applications and challe nges Introduction Basic semiconductor device manufacturing Introduction So, what are they anyway and how are they made? Microfabrication: background and overview Lithography Applications of semiconductor manufacturing MEMS Nanotechnology Background and definitions Nanostructured materials Nanofabrication techniques E-beam and nano-imprint Fabrication Epitaxy and strain engineering Quantum structure nanofabrication using epitaxy on patterned substrates Quantum structure nanofabrication using strain-induced self-assembly 587

12 xiv PRECISION MANUFACTURING Scanned probe techniques Self-assembly MEMS and nanotechnology applications Nanotechnology applications Micro-machining and small scale defects Introduction Surface and edge finish Modeling Finite element modeling Molecular dynamics Multiscale modeling Mechanistic modeling Workpiece and design issues Micromolding Creation of micropattern and microstructure Creation of 3-dimensional shapes Ultrasonic vibration assisted micromachining Micro-tools Cutting fluid Metrology in micromachining Conclusion and outlook Burrs preventing and minimizing burr formation in precision components Introduction and background Process-based solutions Milling Drilling Examples of application of burr minimization strategies Tool path planning in milling Burr control chart Integrated process planning and burr minimization Summary and conclusions 662

13 TABLE OF CONTENTS xv XII. Future of precision manufacturing Introduction The manufacturing pipeline Sustainable design/environmentally conscious design and manufacturing Technologies for sustainable manufacturing Green manufacturing pipeline Sustainable manufacturing or does green = sustainable? Manufacturing technology wedges Examples of wedge technology application areas for manufacturing Consumable use in machining Energy use in nanoscale manufacturing Environmentally conscious design of precision machines Sustainability budgets Constructing the sustainability budget Summary comments/conclusion 701 References 705 Index 765

14 PREFACE & ACKNOWLEDGEMENTS This book is the result of course notes developed for a graduate course on precision manufacturing at Berkeley and taught for the past decade or so. The course was developed to meet the growing need of mechanical engineers, and others, to understand the design and process issues associated with precision machine tools and the fabrication of precision components. It also tried to introduce some fundamental understanding of metrology and the techniques of measurement. These are big topics and we don t claim to cover all to sufficient depth in this book. But, the foundations laid here can be built upon for additional study. The book is designed to compliment a typical 15 week semester course aimed at upper division and graduate level engineering students. The text is extensively referenced so that original sources can be consulted for more details if desired. At Berkeley, some industrial visits to local precision manufacturing firms and several laboratory exercises were included in the semester. These are not outlined in the book. A substantial coverage of some of the historical events driving the development of manufacturing and machine tools is presented in Chapter 1. This is both fascinating as history as well as offers insight into why certain machines and processes are the way they are and the context in which they were developed. References to a number of excellent in depth histories of precision machines and instruments are given for more investigation. This book is not so much an original creative product but the compilation, with insight, order, and some original material added of

15 xviii PRECISION MANUFACTURING course, of a large amount of existing material and expertise. The course notes and, ultimately, this book benefited from a great many contributors, experts in precision engineering worldwide and a special few who either lectured at Berkeley in the class, wrote books covering portions of the topics of interest here, or wrote technical papers published in journals and conference proceedings covering important aspects of precision manufacturing. The actual references are given in the text but a few have had a significant impact on the notes and should be mentioned. A great number of excellent precision engineers have contributed to the book by their lectures, publications and conversations with the authors. Specifically, Professor Pat McKeown of Cranfield University, Professor Ichiro Inasaki of Keio University and Professor Hans-Kurt Tönshoff of the University of Hannover, and the late Professor Juri Tlusty, all spent time visiting Mechanical Engineering at Berkeley as Springer Professors. Their lectures and colloquia as part of their visits offered excellent material to set the tone for and contribute to several sections of this book. Two contributors, Mr. Jim Bryan, retired Chief Metrologist, and Dr. Ken Blaedel, retired precision engineer, both from Lawrence Livermore National Laboratory, lectured to the class, and, through contact at technical meetings and seminal publications in precision engineering, provided much material for the book. The chapter on thermal errors, for example, is based on Dr. Blaedel s short course notes on thermal errors and augmented with Mr. Bryan s technical publications. Professor Alex Slocum of MIT wrote a first excellent book on Precision Machine Design which was used for the class for several years and serves as a competent reference. It is exceptionally detailed and covers the fundamentals of design of machines, fixtures, tooling and related elements. It does not cover manufacturing processes and, hence, this book was necessary. Similarly, Professor Bharat Bhushan of Ohio State University edited a handbook on nanotechnology that includes an impressive volume of information and detail on most aspects of nano-scale device design, processes and fundamentals. This book references both Slocum and Bhushan generously.

16 PREFACE & ACKNOWLEDGEMENTS xix A group of very talented researchers and engineers in precision engineering and machine tool design, control and application contributed to a seven volume review of the state of the art of machine tool technology in the late 1970 s. They represented national laboratories, industry and academia from around the world. Many of the same names listed above appear as authors of major sections of that study. Sponsored by the US Air Force and officially coordinated and published in 1980 by Lawrence Livermore National Laboratory (and, sadly, promptly forgotten by most folks it was designed to benefit in academia and industry), it provided a treasure trove of information on topics ranging from machine control to error budgets to sensor technology to business practices in the industry. You will see extensive reference to this amazing study in this book in several chapters. One of the strings that binds the precision manufacturing community together is the International Academy for Production Engineering (CIRP). Many of the contributors mentioned above are Fellows of this Academy and numerous references to CIRP publications and presentations at the annual meetings provide critical material for this book. CIRP has played a leading role in precision manufacturing research and development for almost 60 years and the CIRP publications, presentations, and conversations of industry, academic, and national laboratory and institute participants in CIRP activities were a treasure trove of basic research and industrial application information. Finally, many past student researchers, postdoctoral researchers, and visiting scholars to the Laboratory for Manufacturing and Sustainability in Mechanical Engineering at Berkeley have contributed to this book in various ways. You will see specific reference to their work throughout the chapters on sensors, process planning, precision machining processes, precision manufacturing applications and sustainable process design. And, in the laboratory, several engineering interns contributed more practically to the production of the book. A number of undergraduate students helped with preparation of images and figures over the years and one, Ms. Maddie Cousens,

17 xx PRECISION MANUFACTURING lead the major effort to secure permissions for material used from other sources. The assistance of all of these individuals and contributions are gratefully appreciated by the authors. David Dornfeld Dae-Eun Lee Berkeley, California August 2007