Corrosion of Ceramic and Composite Materials Copyright © 2004 by Marcel Dekker, Inc. CORROSION TECHNOLOGY Editor Philip A.Schweitzer, P.E. Consultant York, Pennsylvania 1. Corrosion and Corrosion Protection Handbook: Second Edition, Revised and Expanded, edited by Philip A.Schweitzer 2. Corrosion Resistant Coatings Technology, Ichiro Suzuki 3. Corrosion Resistance of Elastomers, Philip A.Schweitzer 4. Corrosion Resistance Tables: Metals, Nonmetals, Coatings, Mortars, Plastics, Elastomers and Linings, and Fabrics: Third Edition, Revised and Expanded (Parts A and B), Philip A.Schweitzer 5. Corrosion-Resistant Piping Systems, Philip A.Schweitzer 6. Corrosion Resistance of Zinc and Zinc Alloys, Frank C.Porter 7. Corrosion of Ceramics, Ronald A.McCauley 8. Corrosion Mechanisms in Theory and Practice, edited by P.Marcus and J.Oudar 9. Corrosion Resistance of Stainless Steels, C.P.Dillon 10. Corrosion Resistance Tables: Metals, Nonmetals, Coatings, Mortars, Plastics, Elastomers and Linings, and Fabrics: Fourth Edition, Revised and Expanded (Parts A, B, and C), Philip A.Schweitzer 11. Corrosion Engineering Handbook, edited by Philip A.Schweitzer 12. Atmospheric Degradation and Corrosion Control, Philip A. Schweitzer 13. Mechanical and Corrosion-Resistant Properties of Plastics and Elastomers, Philip A.Schweitzer 14. Environmental Degradation of Metals, U.K.Chatterjee, S.K.Bose, and S.K.Roy 15. Environmental Effects on Engineered Materials, edited by Russell H.Jones 16. Corrosion-Resistant Linings and Coatings, Philip A.Schweitzer 17. Corrosion Mechanisms in Theory and Practice: Second Edition, Revised and Expanded, edited by Philippe Marcus 18. Electrochemical Techniques in Corrosion Science and Engineering, Robert G.Kelly, John R.Scully, David W.Shoesmith, and Rudolph G.Buchheit 19. Metallic Materials: Physical, Mechanical, and Corrosion Properties, Philip A.Schweitzer Copyright © 2004 by Marcel Dekker, Inc. 20. Encyclopedia of Corrosion Technology: Second Edition, Revised and Expanded, Philip A.Schweitzer 21. Corrosion Resistance Tables: Metals, Nonmetals, Coatings, Mortars, Plastics, Elastomers and Linings, and Fabrics: Fifth Edition, Revised and Expanded (Parts A, B, C, and D), Philip A. Schweitzer 22. Corrosion of Ceramic and Composite Materials: Second Edition, Ronald A.McCauley ADDITIONAL VOLUMES IN PREPARATION Copyright © 2004 by Marcel Dekker, Inc. Corrosion of Ceramic and Composite Materials Second Edition Ronald A.McCauley Rutgers University Piscataway, New Jersey, U.S.A. MARCEL DEKKER, INC.NEW YORK • BASEL Copyright © 2004 by Marcel Dekker, Inc. Transferred to Digital Printing 2004 The first edition was Corrosion of Ceramics (Dekker, 1994). Although great care has been taken to provide accurate and current information, neither the author(s) nor the publisher, nor anyone else associated with this publication, shall be liable for any loss, damage, or liability directly or indirectly caused or alleged to be caused by this book. The material contained herein is not intended to provide specific advice or recommendations for any specific situation. Trademark notice: Product or corporate names may be trademarks or registered trademarks and are used only for identification and explanation without intent to infringe. Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress. ISBN: 0-8247-5366-6 Headquarters Marcel Dekker, Inc., 270 Madison Avenue, New York, NY 10016, U.S.A. tel: 212–696–9000; fax: 212–685–4540 Distribution and Customer Service Marcel Dekker, Inc., Cimarron Road, Monticello, New York 12701, U.S.A. tel: 800–228–1160; fax: 845–796–1772 Eastern Hemisphere Distribution Marcel Dekker AG, Hutgasse 4, Postfach 812, CH-4001 Basel, Switzerland tel: 41–61–260–6300; fax: 41–61–260–6333 World Wide Web The publisher offers discounts on this book when ordered in bulk quantities. For more information, write to Special Sales/Professional Marketing at the head-quarters address above. Copyright © 2004 by Marcel Dekker, Inc. All Rights Reserved. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by any information storage and retrieval system, without permission in writing from the publisher. Current printing (last digit): 10987654321 Copyright © 2004 by Marcel Dekker, Inc. http://www.dekker.com To my father Harry Sylvester McCauley 1909–1966 Copyright © 2004 by Marcel Dekker, Inc. Preface to the Second Edition Although a better understanding of the mechanisms of corrosion has occurred over the past ten years since the publication of the first edition of this book, corrosion still remains a major problem. One area in which some advances have been made is the understanding of the weathering mechanisms of building materials, especially where related to monuments of the past. The weathering of building materials has (Corrosion of Specific Crystalline Materials). Although the work on weathering of building materials has been done predominantly by civil engineers, it should be of interest to the ceramic engineer. More information has become available concerning the corrosion of composite materials of all types. The strong interest in composites materials has been enhanced by the aerospace industry and the military. composite materials. In addition, new sections have been added on all chapters where appropriate. v Copyright © 2004 by Marcel Dekker, Inc. been added as new sections in Chapters 2 (Fundamentals) and 5 Because of this, a whole new chapter (Chapter 7) has been devoted to bioceramics (Chapter 5). New literature sources have been added to The first edition of this book was written to be used primarily as a reference book. Questions have been added at the end of the most chapters and additional examples have been included along with recommended reading lists so that this second edition may also be used as a textbook for either a senior level undergraduate or a graduate course on corrosion. Ronald A.McCauley vi Preface to the Second Edition Copyright © 2004 by Marcel Dekker, Inc. Preface to the First Edition One of the most important problems confronting engineers today is the development of materials that are reliable under various environmental conditions. In some cases these conditions are considered extremely hostile—very high temperatures, mechanical loading, and/or aggressive chemical attack. Ambient temperature aqueous attack can also be extremely detrimental, especially over an extended period of time, as in the case of hazardous waste disposal. Engineers and scientists have been combating the attack upon ceramics of molten glass, molten metals and slags, and molten salts for hundreds of years with many improvements. Most of these improvements have occurred through experimentation, eventually finding the material that worked best. Only during the past 25 years has a true understanding of the complexities of corrosion of ceramics begun to develop. Major advances have been made in recent years; however, the details in many cases are still questionable or at least debatable. The cost to industry due to corrosion is considerable and only a thorough understanding of all the complexities of the process will help vii Copyright © 2004 by Marcel Dekker, Inc. to minimize that cost. There will undoubtedly be many applications of ceramics where the ceramic will be consumed during service, but maximizing service life will greatly reduce the overall cost. While several books, mostly in the form of symposia proceedings, have been published on various aspects of corrosion of crystalline and glassy ceramics, generally on the newer, advanced materials, none has addressed the subject in a comprehensive manner. The most significant works have been reported in the technical literature; however, reading all the published articles is a formidable task. This book is an attempt to discuss all aspects of the corrosion of ceramics, but no attempt has been made to complete an exhaustive literature review. Although not all areas have been described in great detail, a summary of some of the most important work has been given with references for the interested reader. This book is based upon a combination of lecture notes from the Advanced Refractories course that the author has taught at Rutgers during the past 15 years and the author’s industrial and consulting experiences. It is intended predominantly as a reference work for practicing engineers and research scientists but could also be used as a text for a graduate-level course in corrosion of ceramics. Any comments or suggestions about the content of this book will be most welcome. ACKNOWLEDGEMENTS The author would like to thank the faculty and students of the Department of Ceramic and Materials Engineering at Rutgers, The State University of New Jersey, for many helpful and thoughtful discussions during the preparation of this book and especially Drs. John Wachtman and M. John Matthewson for reviewing a portion of the manuscript and for their valuable suggestions. The author would like to extend a very special thank you to Mr. William Englert of PPG Industries, who first introduced the author to the fascinating field of corrosion of ceramics. Gratitude must also be extended to Mrs. Mary Guerin for her help in preparation of the manuscript and to Paul Mort, Robert Sabia, John Martin, and Ryan McCuiston for their help in preparing the figures. The author would like to extend a very special thank you to his wife, Eleanora, and his son, Matthew, for their understanding during the many long hours required to complete this task. Ronald A.McCauley viii Preface to the First Edition Copyright © 2004 by Marcel Dekker, Inc. [...]... Copyright © 2004 by Marcel Dekker, Inc 12 3 12 4 12 6 12 9 13 0 13 0 13 4 13 6 13 9 13 9 14 0 14 0 14 3 14 3 14 9 16 2 16 3 16 4 16 4 Contents 5 CORROSION OF SPECIFIC CRYSTALLINE MATERIALS 5 .1 5.2 5.3 5.4 5.5 Attack by Liquids 5 .1. 1 Attack by Glasses 5 .1. 2 Attack by Aqueous Solutions 5 .1. 3 Attack by Molten Salts 5 .1. 4 Attack by Molten Metals Attack by Gases 5.2 .1 Oxides 5.2.2 Nitrides and Carbides 5.2.3 Borides 5.2.4 Silicides... Questions, and Problems References 7 CORROSION OF COMPOSITE MATERIALS 7 .1 7.2 Introduction Reinforcement Copyright © 2004 by Marcel Dekker, Inc xi 16 5 16 5 16 5 17 7 19 1 19 7 2 01 202 209 2 31 233 234 234 234 235 235 236 237 238 238 257 257 258 2 71 275 276 278 280 2 81 2 81 282 2 91 2 91 295 xii Contents 7.3 7.4 7.5 7.6 7.7 7.2 .1 Fibers 7.2.2 Fiber Coatings or Interphases 7.2.3 Particulates Ceramic Matrix Composites... Thermodynamics 2.7 .1 Mathematical Representation 2.7.2 Graphical Representation 2.8 Kinetics 2.9 Diffusion 2 .10 Summary of Important Concepts 2 .11 Additional Related Reading 2 .12 Exercises, Questions, and Problems References 65 67 67 68 71 77 78 79 85 91 100 10 5 10 7 10 8 10 9 3 METHODS OF CORROSION ANALYSIS 12 3 3 .1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 Introduction Laboratory Test vs Field Trials Sample Selection and Preparation... Only through the intelligent selection of ceramic materials can the cost of corrosion be minimized This intelligent selection of materials can be obtained only through a thorough understanding of all the complexities of Copyright © 2004 by Marcel Dekker, Inc 6 Chapter 1 ceramic materials and the effect that the environment has upon them The corrosion of ceramic materials has not been as well categorized... Edition v vii 1 INTRODUCTION 1 2 FUNDAMENTALS 9 2 .1 Introduction 2.2 Corrosion by Liquids 2.2 .1 Introduction 2.2.2 Crystalline Materials 2.2.3 Glasses 2.3 Corrosion by Gas 2.3 .1 Crystalline Materials 2.3.2 Vacuum 2.3.3 Glasses 9 11 11 15 47 56 56 63 64 ix Copyright © 2004 by Marcel Dekker, Inc x Contents 2.4 Corrosion by Solid 2.5 Surface Effects 2.5 .1 Surface Charge 2.5.2 Porosity and Surface Area... diffusion corrosion, which is very similar to concentration cell corrosion in metals, galvanic cell corrosion, grain boundary corrosion, and stress corrosion A more common trend in ceramic materials is to group corrosion under a more general mechanism, such as dissolution corrosion (i.e., corrosion of a solid by a liquid) In this type of corrosion, diffusion, galvanic cell, grain boundary, and stress corrosion. .. Ceramic Matrix Composites 7.3 .1 Oxide—Matrix Composites 7.3.2 Nonoxide—Matrix Composites Metal Matrix Composites Polymer Matrix Composites Additional Related Reading Exercises, Questions, and Problems References 8 PROPERTIES AND CORROSION 8 .1 8.2 8.3 8.4 8.5 Introduction Mechanisms 8.2 .1 Crystalline Materials 8.2.2 Glassy Materials Degradation of Specific Materials 8.3 .1 Degradation by Oxidation 8.3.2... actual study of corrosion, its causes, effects, and means of elimination is not as common in the field of ceramics as it is in the field of metallurgy Although many engineers study the corrosion of ceramics all their lives, they normally do not consider themselves as corrosion engineers, but as ceramic engineers or process engineers or possibly some other type of engineer There are no corrosion engineering... attempting to understand the corrosion of a ceramic, it is a good idea to remember some of the fundamental concepts of chemistry that are too often forgotten The following are just a few concepts that go a long way in helping one to understand corrosion: 1 A ceramic with acidic character tends to be attacked by an environment with a basic character and vice versa 2 The vapor pressure of covalent materials is... proportional to the square root of the angular velocity [2.9] 2.2.2 Crystalline Materials Attack by Molten Glasses The use of a single diffusion coefficient, as was done in Eqs (2 .1) and (2.2), even in multicomponent systems was verified by Cooper and Kingery [2 .10 ] They, along with Samaddar et al [2 .11 ] and Oishi et al [2 .12 ], described in detail the theory of corrosion by liquids in ceramic systems (i.e., . CRYSTALLINE MATERIALS 16 5 5 .1 Attack by Liquids 16 5 5 .1. 1 Attack by Glasses 16 5 5 .1. 2 Attack by Aqueous Solutions 17 7 5 .1. 3 Attack by Molten Salts 19 1 5 .1. 4 Attack by Molten Metals 19 7 5.2 Attack. 10 5 2 .11 Additional Related Reading 10 7 2 .12 Exercises, Questions, and Problems 10 8 References 10 9 3 METHODS OF CORROSION ANALYSIS 12 3 3 .1 Introduction 12 3 3.2 Laboratory Test vs. Field Trials 12 4 3.3. Edition vii 1 INTRODUCTION 1 2 FUNDAMENTALS 9 2 .1 Introduction 9 2.2 Corrosion by Liquids 11 2.2 .1 Introduction 11 2.2.2 Crystalline Materials 15 2.2.3 Glasses 47 2.3 Corrosion by Gas 56 2.3 .1 Crystalline