ASM INTERNATIONAL ® The Materials Information Company Publication Information and Contributors Friction, Lubrication, and Wear Technology was published in 1992 as Volume 18 of the ASM Handbook. The Volume was prepared under the direction of the ASM International Handbook Committee. Volume Chair The Volume Chairman was Peter J. Blau, Metals and Ceramics Division, Oak Ridge National Laboratory. Authors • Arnold E. Anderson Consultant • Walter K. Arnold Fraunhofer Institute • Betzalel Avitzur Metalforming Inc. • Stephen C. Bayne University of North Carolina • Charles C. Blatchley Spire Corporation • Peter J. Blau Oak Ridge National Laboratory • Raymond H. Boehringer DuBois Chemical Inc. • Royce N. Brown Dow Chemical U.S.A. • Kenneth G. Budinski Eastman Kodak Company • R.F. Bunshah University of California, Los Angeles • Ralph A. Burton Burton Technologies Inc. • Herbert S. Cheng Northwestern University • Stanley Chinowsky Pure Carbon Company • Y W. Chung Northwestern University • Robert D. Compton Noran Instruments Inc. • J.M. Conway-Jones Glacier Vandervell Inc. • Khershed P. Cooper Naval Research Laboratory • Richard S. Cowan Georgia Institute of Technology • Paul Crook Haynes International Inc. • Carl E. Cross Martin Marietta • H. Czichos Bundesanstalt für Materialforschung und -Prüfung (BAM) • Raymond J. Dalley Predict Technologies • Steven Danyluk University of Illinois at Chicago • Mark Davidson University of Florida • Joseph R. Davis Davis & Associates • Duncan Dowson University of Leeds • James F. Dray Mechanical Technology Inc. • David M. Eissenberg Oak Ridge National Laboratory • Peter A. Engel State University of New York at Binghamton • Robert Errichello Geartech • Terry S. Eyre Eyre Associates • Howard N. Farmer Haynes International Inc. • Richard S. Fein Fein Associates • George R. Fenske Argonne National Laboratory • Paul D. Fleischauer Aerospace Corporation • Dudley D. Fuller Columbia University • William A. Glaeser Battelle Memorial Institute • Douglas A. Granger Aluminum Company of America • Austin L. Grogan, Jr. University of Central Florida • Inge L.H. Hansson Alcan International Ltd. • Carolyn M. Hansson Queen's University • Tedric A. Harris Pennsylvania State University • Howard D. Haynes Oak Ridge National Laboratory • Per Hedenqvist Uppsala University • Frank J. Heymann Consultant • Michael R. Hilton Aerospace Corporation • Franz Hoffmann Stiftung Institut für Werkstofftechnik • Sture Hogmark Uppsala University • Roger G. Horn National Institute of Standards and Technology • C.R. Houska Virginia Polytechnic Institute • Lewis K. Ives National Institute of Standards and Technology • Staffan Jacobsson Uppsala University • William R. Kelley Borg-Warner Automotive • L. Alden Kendall University of Minnesota, Duluth • Francis E. Kennedy, Jr. Dartmouth College • George R. Kingsbury Glacier Vandervell Inc. • Thomas H. Kosel University of Notre Dame • Burton A. Kushner Metco/Perkin-Elmer • Frank M. Kustas Martin Marietta Aerospace • Joseph T. Laemmle Aluminum Company of America • Jorn Larsen-Basse National Science Foundation • Soo-Wohn Lee University of Illinois at Chicago • A.V. Levy Lawrence Berkeley Laboratory • Y. Liu University of Wisconsin-Milwaukee • Frances E. Lockwood Pennzoil Products Company • Kenneth C. Ludema University of Michigan • Brent W. Madsen U.S. Bureau of Mines • John H. Magee Carpenter Technology Corporation • James L. Maloney III Latrobe Steel • William D. Marscher Dresser Industries • Hugh R. Martin University of Waterloo • P. Mayr Stiftung Institut für Werkstofftechnik • John E. Miller White Rock Engineering Inc. • Mohan S. Misra Martin Marietta Aerospace • Charles A. Moyer Timken Company • U. Netzelmann Fraunhofer Institute • Edward R. Novinski Metco/Perkin-Elmer • David L. Olson Colorado School of Mines • Michael Olsson Uppsala University • S. Pangraz Fraunhofer Institute • Ron Pike Glacier Vandervell Inc. • Padmanabha S. Pillai Goodyear Tire & Rubber Company • Hubert M. Pollock Lancaster University • John M. Powers University of Texas • Terence F.J. Quinn United States International University • S. Ray University of Wisconsin-Milwaukee • Stephen L. Rice University of Central Florida • Syed Q.A. Rizvi Lubrizol Corporation • Pradeep Rohatgi University of Wisconsin-Milwaukee • A.W. Ruff National Institute of Standards and Technology • John Rumierz SKF USA Inc. • Leonard E. Samuels Samuels Consultants • Jerry D. Schell General Electric Aircraft Engines • Monica A. Schmidt Martin Marietta Energy Systems Inc. • Henry J. Scussel GTE Valenite • S.L. Semiatin Wright Laboratory • Barrie S. Shabel Aluminum Company of America • Keith Sheppard Stevens Institute of Technology • Rajiv Shivpuri Ohio State University • Harold E. Sliney NASA Lewis Research Center • J.F. Song National Institute of Standards and Technology • T.S. Sriram Northwestern University • Charles A. Stickels Environmental Research Institute of Michigan • E.M. Tatarzycki Aircraft Braking Systems Corporation • Kevin P. Taylor General Electric Aircraft Engines • William G. Truckner Aluminum Company of America • Joseph H. Tylczak U.S. Bureau of Mines • Olof Vingsbo Uppsala University • T.V. Vorburger National Institute of Standards and Technology • Robert B. Waterhouse University of Nottingham • R.T. Webb Aircraft Braking Systems Corporation • Rolf Weil Stevens Institute of Technology • Eric P. Whitenton National Institute of Standards and Technology • Ward O. Winer Georgia Institute of Technology Reviewers and Contributors • Taylan Altan Ohio State University • Doug Asbury Cree Research • Shyam Bahadur Iowa State University • Randall F. Barron Louisiana Tech University • Raymond Bayer Consultant • Abdel E. Bayoumi Washington State University • Horst Becker Sintermet Corporation • Charles Bellanca Dayton Power and Light • Robert K. Betts Cincinnati Thermal Spray Inc. • Peter J. Blau Oak Ridge National Laboratory • Rodney R. Boyer Boeing Commercial Airplane Group • Robert W. Bruce General Electric Aircraft Engines • Gerald Bruck Westinghouse STC • Michael Bryant University of Texas • R.A. Buchanan University of Tennessee, Knoxville • Kenneth G. Budinski Eastman Kodak Company • Harold I. Burrier, Jr. Timken Company • Donald C. Carmichael Battelle Memorial Institute • J.A. Carpenter, Jr. National Institute of Standards and Technology • A.G. Causa Goodyear Tire & Rubber Company • Y.P. Chiu Torrington Company • Ronald Christy Tribo Coating • Richard S. Cowan Georgia Institute of Technology • W.J. Crecelius General Electric • G.R. Crook Aluminum Company of America • Bob Dawson Deloro Stellite Inc. • Arnold O. DeHart Bearing Systems Technology • Christopher DellaCorte NASA Lewis Research Center • Paolo DeTassis Clevite SpA • John Deuber Degussa Corporation • Mitchell R. Dorfman Metco/Perkin-Elmer • Keith Dufrane Battelle Memorial Institute • Lawrence D. Dyer Dyer Consultants • Norman S. Eiss, Jr. Virginia Polytechnic Institute and State University • Wayne L. Elban Loyola College • T.N. Farris Purdue University • Neal Fechter National Electric Carbon Corporation • Andrew Fee Wilson Instruments • Richard S. Fein Fein Associates • Gregory A. Fett Dana Corporation • Traugott Fischer Stevens Institute of Technology • Donald G. Flom Flom Consulting • Anna C. Fraker National Institute of Standards and Technology • Steven G. Fritz Southwest Research Institute • Raymond P. Funk Cato Oil & Grease Company • Michelle M. Gauthier Raytheon Company • Louis T. Germinario Eastman Chemical Company • S.K. Ghosh Eastman Kodak Company • W.A. Glaeser Battelle Memorial Institute • E.W. Glossbrenner Litton Poly-Scientific • Allan E. Goldman U.S. Graphite Inc. • Steven Granick University of Illinois • Robert E. Green, Jr. Johns Hopkins University • Walter P. Groff Southwest Research Institute • John J. Groth FMC Corporation • Raymond A. Guyer, Jr. Rolling Bearing Institute Ltd. • Tom Heberling Armco Inc. Research Laboratories • Frank Heymann Consultant • Robert Hochman Georgia Institute of Technology • James C. Holzwarth General Motors Research Laboratories (Retired) • Hyun-Soo Hong Lubrizol Corporation • James Hudson A-C Compressor Corporation • Allan B. Hughes Actis Inc. • S. Ibarra Amoco Corporation Research • J. Ernesto Indacochea University of Illinois at Chicago • Said Jahanmir National Institute of Standards and Technology • Bob Jaklevic Ford Motor Company • Kishore Kar Dow Chemical Company • Igor J. Karassik Dresser Pump Division, Dresser Industries • Francis E. Kennedy, Jr. Dartmouth College • M.K. Keshavan Smith International • L.L. Kesmodel Indiana University • Paul Y. Kim National Research Council • George Krauss Colorado School of Mines • Jorn Larsen-Basse National Science Foundation • P.W. Lee Timken Company • Minyoung Lee General Electric Company • Herman R. Leep University of Louisville • Kenneth Liebler • Richard Lindeke University of Minnesota • Walter E. Littmann Failure Analysis Associates Inc. • Stephen Liu Colorado School of Mines • Frances E. Lockwood Pennzoil Products Company • Robert A. Lord Dresser-Rand Company • William Lucke Cincinnati Milacron • Kenneth C. Ludema University of Michigan • William L. Mankins Inco Alloys International Inc. • Jacques Masounave E.T.S. Université du Québec • I.D. Massey Glacier Vandervell Ltd. • P.M. McGuiggan 3M Company • Paul Mehta General Electric Aircraft Engines • John E. Miller White Rock Engineering Inc. • John C. Mitchem Oregon Health Sciences University • K. Miyoshi NASA Lewis Research Center • P.A. Molian Iowa State University • Dave Neff Metaullics Systems • Welville B. Nowak Northeastern University • Han Nyo BP Chemicals (Hitco) Inc. • Warren Oliver Oak Ridge National Laboratory • David L. Olson Colorado School of Mines • Daniel W. Parker General Plasma • Konrad Parker Consultant • Sanjay Patel AT&T Bell Laboratories • Burton R. Payne, Jr. Payne Chemical Corporation • Marshall B. Peterson Wear Sciences Corporation • William W. Poole United Technologies Corporation • Marion L. Pottinger Smithers Scientific Services Inc. • K. Prewo United Technologies Research Center • C. Pulford Goodyear Tire & Rubber Company • J. Raja University of North Carolina at Charlotte • Seong K. Rhee Allied-Signal Friction Materials • Stephen L. Rice University of Central Florida • David A. Rigney Ohio State University • Gary Rimlinger Aircraft Braking Systems Corporation • Michael L. Rizzone Consulting Mechanical Engineer • Elwin L. Rooy Consultant • Jules Routbort Argonne National Laboratory • A.W. Ruff National Institute of Standards and Technology • Nannaji Saka Massachusetts Institute of Technology • Ronald O. Scattergood North Carolina State University • J.A. Schey University of Waterloo • George F. Schmitt, Jr. • William Schumacher Armco Research & Technology • Christopher G. Scott Lubrizol Corporation • Wilbur Shapiro Mechanical Technology Inc. • Hal Shaub Exxon Chemical Company • M.C. Shaw Arizona State University • Lewis B. Sibley Tribology Systems Inc. • Fred A. Smidt Naval Research Laboratory • Darrell W. Smith Michigan Technological University • Talivaldis Spalvins NASA Lewis Research Center • Cullie J. Sparks, Jr. Oak Ridge National Laboratory • Donald R. Spriggs Chem-tronics Aviation Repair • Karl J. Springer Southwest Research Institute • William D. Sproul BIRL Northwestern University • D.S. Stone University of Wisconsin • W. Sutton United Technologies Research Center • Shoji Suzuki Asahi Glass America Inc. • Paul A. Swanson Deere & Company • Roderic V. Sweet MRC Bearing Services • A.R. Thangaraj Michigan Technological University • Frank Toye Leco Corporation • Ronald L. Trauger • George Vander Voort Carpenter Technology Corporation • William von Kampen General Motors Truck & Bus • Roy Waldheger Carbon Technology Inc. • Malcolm J. Werner Bently Nevada • Grady S. White National Institute of Standards and Technology • Eric P. Whitenton National Institute of Standards and Technology • Douglas D. Wilson Friction Products Company • Ward O. Winer Georgia Institute of Technology • Jerry O. Wolfe Timken Company • William A. Yahraus Failure Analysis Associates Inc. • William B. Young Dana Corporation • Charles S. Yust Oak Ridge National Laboratory • G. Zajac Amoco Research Center • Dong Zhu Alcoa Technical Center Foreword The publication of this Volume marks the first time that the ASM Handbook has dealt with friction, lubrication, and wear technology as a separate subject. However, the tribological behavior of materials and components has been of fundamental importance to ASM members throughout the history of the Society. ASM International traces its origins back to 1913 with the formation of the Steel Treaters Club in Detroit. This group joined with the American Steel Treaters Society to form the American Society for Steel Treating in 1920. In the early history of the Society as an organization devoted primarily to heat treating, one of the key interests of its membership was improving the wear properties of steel. In 1933 the organization changed its name to the American Society for Metals, completing its transformation to an organization that served the interests of the entire metals industry. This change led the Society into many other areas such as metalworking, surface finishing, and failure analysis where friction, lubrication, and wear are key concerns. In 1987 the technical scope of the Society was further broadened to include the processing, properties, and applications of all engineering/structural materials, and thus ASM International was born. This Handbook reflects the wide focus of the Society by addressing the tribological behavior of a broad range of materials. The comprehensive coverage provided by this Volume could not have been achieved without the planning and coordination of Volume Chairman Peter J. Blau. He has been tireless in his efforts to make this Handbook the most useful tool possible. Thanks are also due to the Section Chairmen, to the members of the ASM Handbook Committee, and to the ASM editorial staff. We are especially grateful to the over 250 authors and reviewers who so generously donated their time and expertise to make this Handbook an outstanding source of information. • William P. Koster President ASM International • Edward L. Langer Managing Director ASM International Preface Friction, lubrication, and wear (FL&W) technology impacts many aspects of daily life, from the wear of one's teeth to the design of intricate, high-speed bearings for the space shuttle. Nearly everyone encounters a FL&W problem from time to time. Sometimes the solution to the problem is simple and obvious disassembling, cleaning, and relubricating a door hinge, for example. Sometimes, however, the problem itself is difficult to define, the contact conditions in the system difficult to characterize, and the solution elusive. Approaches to problem-solving in the multidisciplinary field of tribology (that is, the science and technology of FL&W) often present a wide range of options and can include such diverse fields as mechanical design, lubrication, contact mechanics, fluid dynamics, surface chemistry, solid-state physics, and materials science and engineering. Practical experience is a very important resource for solving many types of FL&W problems, often replacing the application of rigorous tribology theory or engineering equations. Selecting "the right tool for the right job" was an inherent principle in planning the contents of this Volume. It is unrealistic to expect that specific answers to all conceivable FL&W problems will be found herein. Rather, this Handbook has been designed as a resource for basic concepts, methods of laboratory testing and analysis, materials selection, and field diagnosis of tribology problems. As Volume Chairman, I asked the Handbook contributors to keep in mind the question: "What information would I like to have on my desk to help me with friction, lubrication, or wear problems?" More than 100 specialized experts have risen to this challenge, and a wealth of useful information resides in this book. The sections on solid friction, lubricants and lubrication, and wear and surface damage contain basic, tutorial information that helps introduce the materials-oriented professional to established concepts in tribology. The Handbook is also intended for use by individuals with a background in mechanics or lubricant chemistry and little knowledge of materials. For example, some readers may not be familiar with the measurement and units of viscosity or the regimes of lubrication, and others may not know the difference between brass and bronze. The "Glossary of Terms" helps to clarify the use of terminology and jargon in this multidisciplinary area. The discerning reader will find the language of FL&W technology to be somewhat imprecise; consequently, careful attention to context is advised when reading the different articles in the Volume. The articles devoted to various laboratory techniques for conducting FL&W analyses offers a choice of tools to the reader for measuring wear accurately, using these measurements to compute wear rates, understanding and interpreting the results of surface imaging techniques, and designing experiments such that the important test variables have been isolated and controlled. Because many tribosystems contain a host of thermal, mechanical, materials, and chemical influences, structured approaches to analyzing complex tribosystems have also been provided. The articles devoted to specific friction- or wear-critical components are intended to exemplify design and materials selection strategies. A number of typical tribological components or classes of components are described, but it was obviously impossible to include all the types of moving mechanical assemblies that may experience FL&W problems. Enough diversity is provided, however, to give the reader a solid basis for attacking other types of problems. The earlier sections dealing with the basic principles of FL&W science and technology should also be useful in this regard. Later sections of the Handbook address specific types of materials and how they react in friction and wear situations. Irons, alloy steels, babbitts, and copper alloys (brasses and bronzes) probably account for the major tonnage of tribological materials in use today, but there are technologically important situations where these workhorse materials may not be appropriate. Readers with tribomaterials problems may find the sections on other materials choices, such as carbon-graphites, ceramics, polymers, and intermetallic compounds, helpful in providing alternate materials-based solutions. In addition, the section on surface treatments and modifications should be valuable for attacking specialized friction and wear problems. Again, the point is to find the right material for the right job. This Volume marks the first time that ASM International has compiled a handbook of FL&W technology. The tribology research and development community is quite small compared with other disciplines, and the experts who agreed to author articles for this Volume are extremely busy people. I am delighted that such an outstanding group of authors rallied to the cause, one that ASM and the entire tribology community can take pride in. I wish to thank all the contributors heartily for their much-appreciated dedication to this complex and important project in applied materials technology. • Peter J. Blau, Volume Chairman Metals and Ceramics Division Oak Ridge National Laboratory General Information Officers and Trustees of ASM International (1991-1992) • William P. Koster President and Trustee Metcut Research Associates Inc. • Edward H. Kottcamp, Jr. Vice President and Trustee SPS Technologies • Stephen M. Copley Immediate Past President and Trustee Illinois Institute of Technology • Edward L. Langer Secretary and Managing Director ASM International • Leo G. Thompson Treasurer Lindberg Corporation • Trustees • William H. Erickson Canada Centre for Minerals & Energy Technology • Norman A. Gjostein Ford Motor Company • Nicholas C. Jessen, Jr. Martin Marietta Energy Systems, Inc • E. George Kendall Northrop Aircraft • George Krauss Colorado School of Mines • Kenneth F. Packer Packer Engineering, Inc. • Hans Portisch VDM Technologies Corporation • Lyle H. Schwartz National Institute of Standards and Technology • John G. Simon General Motors Corporation Members of the ASM Handbook Committee (1991-1992) • David LeRoy Olson(Chairman 1990-; Member 1982-1988; 1989-) Colorado School of Mines • Ted Anderson (1991-) Texas A&M University • Roger J. Austin (1984-) Hydro-Lift • Robert J. Barnhurst (1988-) Noranda Technology Centre • John F. Breedis (1989-) Olin Corporation • Stephen J. Burden (1989-) GTE Valenite • Craig V. Darragh (1989-) The Timken Company • Russell J. Diefendorf (1990-) Clemson University • Aicha Elshabini-Riad (1990-) Virginia Polytechnic & State University • Michelle M. Gauthier (1990-) Raytheon Company • Toni Grobstein (1990-) NASA Lewis Research Center • Susan Housh (1990-) Dow Chemical U.S.A. • Dennis D. Huffman (1982-) The Timken Company • S. Jim Ibarra (1991-) Amoco Research Center • J. Ernesto Indacochea (1987-) University of Illinois at Chicago • Peter W. Lee (1990-) The Timken Company • William L. Mankins (1989-) Inco Alloys International, Inc. • David V. Neff (1986-) Metaullics Systems • Richard E. Robertson (1990-) University of Michigan • Elwin L. Rooy (1989-) Consultant • Jeremy C. St. Pierre (1990-) Hayes Heat Treating Corporation • Ephraim Suhir (1990-) AT&T Bell Laboratories • Kenneth Tator (1991-) KTA-Tator, Inc. • William B. Young (1991-) Dana Corporation Previous Chairmen of the ASM Handbook Committee • R.S. Archer (1940-1942) (Member, 1937-1942) • L.B. Case (1931-1933) (Member, 1927-1933) • T.D. Cooper (1984-1986) (Member, 1981-1986) • E.O. Dixon (1952-1954) (Member, 1947-1955) • R.L. Dowdell (1938-1939) (Member, 1935-1939) • J.P. Gill (1937) (Member, 1934-1937) • J.D. Graham (1966-1968) (Member, 1961-1970) • J.F. Harper (1923-1926) (Member, 1923-1926) • C.H. Herty, Jr. (1934-1936) (Member, 1930-1936) • D.D. Huffman (1986-1990) (Member, 1990-) • J.B. Johnson (1948-1951) (Member, 1944-1951) • L.J. Korb (1983) (Member, 1978-1983) • R.W.E. Leiter (1962-1963) (Member, 1955-1958, 1960-1964) • G.V. Luerssen (1943-1947) (Member, 1942-1947) • G.N. Maniar (1979-1980) (Member, 1974-1980) • J.L. McCall (1982) (Member, 1977-1982) • W.J. Merten (1927-1930) (Member, 1923-1933)) • N.E. Promisel (1955-1961) (Member, 1954-1963) • G.J. Shubat (1973-1975) (Member, 1966-1975) • W.A. Stadtler (1969-1972) (Member, 1962-1972) • R. Ward (1976-1978) (Member, 1972-1978) • M.G.H. Wells (1981) (Member, 1976-1981) • D.J. Wright (1964-1965) (Member, 1959-1967) Staff ASM International staff who contributed to the development of the Volume included Scott D. Henry, Editor, ASM Handbooks; Grace M. Davidson, Production Project Manager; Theodore B. Zorc, Technical Editor; Dawn Levicki, Editorial Assistant; Robert C. Uhl, Director of Reference Publications. Editorial assistance was provided by Joseph R. Davis, Kelly Ferjutz, Heather Lampman, Kathleen M. Mills, Nikki D. Wheaton, and Mara S. Woods. Conversion to Electronic Files ASM Handbook, Volume 18, Friction, Lubrication, and Wear Technology was converted to electronic files in 1997. The conversion was based on the Second Printing (March 1995). No substantive changes were made to the content of the Volume, but some minor corrections and clarifications were made as needed. ASM International staff who contributed to the conversion of the Volume included Sally Fahrenholz-Mann, Bonnie Sanders, Scott Henry, Grace Davidson, Randall Boring, Robert Braddock, Kathleen Dragolich, and Audra Scott. The electronic version was prepared under the direction of William W. Scott, Jr., Technical Director, and Michael J. DeHaemer, Managing Director. Copyright Information (for Print Volume) Copyright © 1992 by ASM International All Rights Reserved. ASM Handbook is a collective effort involving thousands of technical specialists. It brings together in one book a wealth of information from world-wide sources to help scientists, engineers, and technicians solve current and long-range problems. Great care is taken in the compilation and production of this Volume, but it should be made clear that no warranties, express or implied, are given in connection with the accuracy or completeness of this publication, and no responsibility can be taken for any claims that may arise. Nothing contained in the ASM Handbook shall be construed as a grant of any right of manufacture, sale, use, or reproduction, in connection with any method, process, apparatus, product, composition, or system, whether or not covered by letters patent, copyright, or trademark, and nothing contained in the ASM Handbook shall be construed as a defense against any alleged infringement of letters patent, copyright, or trademark, or as a defense against liability for such infringement. Comments, criticisms, and suggestions are invited, and should be forwarded to ASM International. [...]... Cataloging-in -Publication Data (for Print Volume) ASM International ASM Handbook Title proper has changed with v.4: ASM Handbook Vol 18: Prepared under the direction of the ASM International Handbook Committee Includes bibliographies and indexes Contents: v 18 Friction, lubrication, and wear technology 1 Metals Handbooks, manuals, etc I ASM International Handbook Committee II Title: ASM Handbook TA459.M43... that friction is caused by a ratcheting effect and that the friction work is the work to lift one body over the asperities of the other The asperities would have a slope equal to or less than the friction angle Euler developed the first clearly analytical approach to friction and treated it is an integral part of the mechanics of bodies in motion He was also the first to use for the coefficient of friction. .. efficiently and reliably It is useful to clearly separate the various terms and concepts associated with friction, such as "friction force," "friction coefficient," "frictional energy," and "frictional heating." These terms are defined below and in the "Glossary of Terms" in this Volume The friction force is the tangential force that must be overcome in order for one solid contacting body to slide over another... coefficient of friction, k A body on a flat surface will begin to move due to gravity if the surface is raised to the friction angle, , where: s = tan (Eq 2) See Fig 1 in the article "Introduction to Friction" in this Volume To overcome friction, the tangential force must be applied over the entire sliding distance; the product of the two is friction work The resulting energy is lost to heat in the in the form... little or nothing to do with the nature of the contacting materials As the two surfaces are brought closer together, the asperities begin to come in contact and the zone of so-called "boundary lubrication" is entered The degree of separation between the two surfaces can be measured by the ratio of the mean gap distance, h, to the composite roughness of the two opposing surfaces, The composite roughness... be close to the hardness of the softer material; plastic deformation takes place on a very local scale, and cold welding may form strongly bonded junctions between the two materials When sliding begins, these junctions have to be broken by the friction force, and this provides the adhesive component of the friction Some asperities may plow across the surface of the mating material, and the resulting... which can be called the "plane stress modulus." If the two materials are identical, E' is half of this In Eq 5, H is the indentation hardness (in N/m2), is the standard deviation of the asperity height distribution, and is the radius of the asperity tips The plasticity index combines mechanical properties (E' and H and topographical properties ( and ) of the solids in contact Greenwood and Williamson (Ref... slip-line field analysis The nature of the deformation under a blunt wedge depends on the interface friction between the wedge face and the surface of the metal (see Fig 11 for a rigid, perfectly plastic material) If the friction is large, a cap of restrained material that does not flow plastically will form below the tip of the wedge If the friction is zero, no such cap develops and the metal deformation... with the work of Bowden and Tabor in the mid-20th century (Ref 16) Their work focused on adhesion as a major cause of friction, but also showed that more than the outermost layers is involved that is, that both adhesion and deformation of the substance material are important contributors to the energy dissipation in friction The adhesion theory of friction is often attributed to Bowden and Tabor, and, ... surface layers due to change in composition, and formation of compounds by chemical or mechanical action The nature and the effects of all of these depend on the specific situation For pure, film free surfaces in a vacuum, the adhesive friction depends on the size of the adhesion are, the strength of the adhesive bonds, and, in most cases, on the flow stress of the subsurface material, because that is . The Materials Information Company Publication Information and Contributors Friction, Lubrication, and Wear Technology was published in 1992 as Volume 18 of the ASM Handbook. The Volume. Center Foreword The publication of this Volume marks the first time that the ASM Handbook has dealt with friction, lubrication, and wear technology as a separate subject. However, the tribological. ASM Handbook. Vol. 18: Prepared under the direction of the ASM International Handbook Committee. Includes bibliographies and indexes. Contents: v. 18. Friction, lubrication, and wear technology