WEAR – MATERIALS, MECHANISMS AND PRACTICE Editors: M.J. Neale, T.A. Polak and M. Priest Guide to Wear Problems and Testing for Industry M.J. Neale and M. Gee Handbook of Surface Treatment and Coatings M. Neale, T.A. Polak, and M. Priest (Eds) Lubrication and Lubricant Selection – A Practical Guide, 3rd Edition A.R. Lansdown Rolling Contacts T.A. Stolarski and S. Tobe Total Tribology – Towards an integrated approach I. Sherrington, B. Rowe and R. Wood (Eds) Tribology – Lubrication, Friction and Wear I.V. Kragelsky, V.V. Alisin, N.K. Myshkin and M.I. Petrokovets Wear – Materials, Mechanisms and Practice G. Stachowiak (Ed.) WEAR – MATERIALS, MECHANISMS AND PRACTICE Edited by Gwidon W. Stachowiak Copyright © 2005 John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ, England Telephone (+44) 1243 779777 Chapter 1 Copyright © I.M. Hutchings Email (for orders and customer service enquiries): [email protected] Visit our Home Page on www.wiley.com Reprinted with corrections May 2006 All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except under the terms of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London W1T 4LP, UK, without the permission in writing of the Publisher. Requests to the Publisher should be addressed to the Permissions Department, John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ, England, or emailed to [email protected], or faxed to (+44) 1243 770620. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the Publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought. Other Wiley Editorial Offices John Wiley & Sons Inc., 111 River Street, Hoboken, NJ 07030, USA Jossey-Bass, 989 Market Street, San Francisco, CA 94103-1741, USA Wiley-VCH Verlag GmbH, Boschstr. 12, D-69469 Weinheim, Germany John Wiley & Sons Australia Ltd, 42 McDougall Street, Milton, Queensland 4064, Australia John Wiley & Sons (Asia) Pte Ltd, 2 Clementi Loop #02-01, Jin Xing Distripark, Singapore 129809 John Wiley & Sons Canada Ltd, 22 Worcester Road, Etobicoke, Ontario, Canada M9W 1L1 Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. Library of Congress Cataloging in Publication Data Wear – materials, mechanisms and practice / editor Gwidon W. Stachowiak. p. cm. Includes bibliographical references and index. ISBN-13: 978-0-470-01628-2 (cloth : alk. paper) ISBN-10: 0-470-01628-0 (cloth : alk. paper) 1. Mechanical wear. I. Stachowiak, G.W. (Gwidon W.) TA418.4.W415 2005 620.1'1292—dc22 2005006833 British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN-13: 978-0-470-01628-2 (HB) ISBN-10: 0-470-01628-0 (HB) Typeset in 10/12pt Times by Integra Software Services Pvt. Ltd, Pondicherry, India Printed and bound in Great Britain by Antony Rowe Ltd, Chippenham, Wiltshire This book is printed on acid-free paper responsibly manufactured from sustainable forestry in which at least two trees are planted for each one used for paper production. Contents List of Contributors xiii Series Editors’ Foreword xvii Preface xix 1 The Challenge of Wear 1 I.M. Hutchings Abstract 1 1.1 Introduction 1 1.2 Definitions and Development of Wear Studies 1 1.3 Scope and Challenges 2 1.4 Conclusions 6 References 6 2 Classification of Wear Mechanisms/Models 9 K. Kato Abstract 9 2.1 Introduction 9 2.2 Classification of Wear Mechanisms and Wear Modes 10 2.2.1 Mechanical, Chemical and Thermal Wear 10 2.2.2 Wear Modes: Abrasive, Adhesive, Flow and Fatigue Wear 11 2.2.3 Corrosive Wear 14 2.2.4 Melt and Diffusive Wear 15 2.3 General Discussion of Wear Mechanisms and Their Models 15 2.3.1 Material Dependence 15 2.3.2 Wear Maps 16 2.3.3 Wear Mode Transition 17 2.3.4 Erosion 17 2.4 Conclusion 18 Acknowledgements 18 References 18 3 Wear of Metals: A Material Approach 21 S.K. Biswas Abstract 21 3.1 Introduction 21 vi Contents 3.2 Mild Wear and Transition to Severe Wear 22 3.2.1 Mild Wear 22 3.2.2 Transition to Severe Wear 23 3.3 Strain Rate Estimates and Bulk Surface Temperature 27 3.3.1 Strain Rate Response Maps 28 3.3.2 Bulk Surface Temperature 30 3.3.3 The Phenomenological Argument 30 3.3.4 Micrographic Observations 31 3.4 Summary 34 3.4.1 Homogeneous Deformation – Severe Wear 34 3.4.2 Homogeneous Deformation – Mild Wear 35 3.4.3 Inhomogeneous Deformation – Severe Wear 35 Acknowledgements 35 References 35 4 Boundary Lubricated Wear 37 S.M. Hsu, R.G. Munro, M.C. Shen, and R.S. Gates Abstract 37 4.1 Introduction 37 4.2 Lubricated Wear Classification 38 4.3 Lubricated Wear Versus “Dry” Wear 38 4.4 Wear Measurement in Well-Lubricated Systems 42 4.5 Measurement Procedures 44 4.5.1 Run-In Process 46 4.5.2 General Performance Wear Test (GPT) 49 4.5.3 Enhanced Oxidation Wear Test (EOT) 52 4.5.4 Boundary Film Persistence Test (BFPT) 53 4.5.5 Case Study with GPT and BFPT 55 4.5.6 Boundary Film Failure Test (BFFT) 57 4.6 Wear Mechanisms Under Lubricated Conditions 61 4.7 Modeling of Lubricated Wear 65 4.7.1 Wear 65 4.7.2 Contact Area 65 4.7.3 Rheology 66 4.7.4 Film Thickness 67 4.7.5 Contact Stress 67 4.7.6 Flash Temperatures 67 4.8 Summary 68 Acknowledgments 69 References 69 5 Wear and Chemistry of Lubricants 71 A. Neville and A. Morina 5.1 Encountering Wear in Tribological Contacts 71 5.2 Lubricant Formulations – Drivers for Change 73 5.3 Tribochemistry and Wear 76 5.4 Antiwear Additive Technologies 77 5.4.1 Antiwear Technologies 77 5.4.2 ZDDP – Antiwear Mechanism 78 Contents vii 5.4.3 Interaction of ZDDP with Other Additives 83 5.4.4 New Antiwear Additive Technologies 87 5.5 Extreme Pressure Additives 88 5.6 Lubricating Non-Fe Materials 89 References 90 6 Surface Chemistry in Tribology 95 A.J. Gellman and N.D. Spencer Abstract 95 6.1 Introduction 95 6.2 Boundary Lubrication and Oiliness Additives 95 6.2.1 Introduction 95 6.2.2 Monolayers, Multilayers and Soaps 96 6.2.3 Viscous Near-Surface Layers 102 6.2.4 Boundary Lubrication in Natural Joints 102 6.2.5 Summary 103 6.3 Zinc Dialkyldithiophosphate 103 6.3.1 Background 103 6.3.2 Analytical Approaches 104 6.3.3 Summary of Film-Formation Mechanism 104 6.3.4 Studies of Film Structure, Composition, and Thickness 105 6.4 Hard Disk Lubrication 109 6.5 Vapor-Phase Lubrication 112 6.6 Tribology of Quasicrystals 115 6.7 Conclusions 118 Acknowledgments 118 References 118 7 Tribology of Engineered Surfaces 123 K. Holmberg and A. Matthews Abstract 123 7.1 Introduction 123 7.2 Definition of an Engineered Surface 125 7.3 Tribomechanisms of Coated Surfaces 125 7.3.1 Scales of Tribology 125 7.3.2 Macromechanical Friction and Wear 126 7.3.3 Micromechanical Mechanisms 131 7.3.4 Modelling Stresses and Strains in a Coated Microcontact 132 7.3.5 Tribochemical Mechanisms 133 7.3.6 Nanoscale Mechanisms 135 7.3.7 Debris Generation and Transfer Layers 136 7.4 Contact Types 139 7.4.1 Sliding 139 7.4.2 Abrasion 141 7.4.3 Impact 141 7.4.4 Surface Fatigue 141 7.4.5 Fretting 142 7.4.6 Chemical Dissolution 143 7.4.7 Lubricated 143 viii Contents 7.5 Advanced Coating Types 144 7.5.1 Hard Binary Compound Coatings 145 7.5.2 Multilayer Coatings 146 7.5.3 Nanocomposite Coatings 149 7.5.4 Hybrid and Duplex Coatings 151 7.6 Applications 152 7.7 Conclusions 154 References 155 8 Wear of Ceramics: Wear Transitions and Tribochemical Reactions 167 S. Jahanmir Abstract 167 8.1 Introduction 168 8.2 Structure and Properties of Ceramics 168 8.2.1 Alumina Ceramics 168 8.2.2 Silicon Nitride Ceramics 169 8.2.3 Silicon Carbide Ceramics 170 8.3 Wear Transitions 170 8.3.1 Alumina 171 8.3.2 Silicon Nitride 174 8.3.3 Silicon Carbide 175 8.4 Damage Formation in Hertzian Contacts 177 8.4.1 Brittle Behavior 177 8.4.2 Quasi-Plastic Behavior 177 8.4.3 Brittleness Index 180 8.5 Transition Loads in Sliding Contacts 181 8.5.1 Quasi-Plastic Behavior 181 8.5.2 Brittle Behavior 183 8.5.3 Transition from Brittle Fracture to Quasi-Plasticity 184 8.6 Ceramics in Tribological Applications 185 Acknowledgments 187 References 187 9 Tribology of Diamond and Diamond-Like Carbon Films: An Overview 191 A. Erdemir and Ch. Donnet Abstract 191 9.1 General Overview 192 9.2 Diamond Films 194 9.2.1 Deposition and Film Microstructure 194 9.2.2 Tribology of Diamond Films 195 9.2.3 Practical Applications 204 9.3 Diamond-like Carbon Films 207 9.3.1 Structure and Composition 207 9.3.2 Tribology of DLC Films 209 9.3.3 Synthesis of Carbon Films with Superlow-Friction and -Wear Properties 215 9.3.4 Practical Applications 217 9.4 Summary and Future Direction 219 Acknowledgments 219 References 220 Contents ix 10 Tribology of Polymeric Solids and Their Composites 223 B.J.