Vol. 28, No. 6, pp. 421-422, 1995 Limited. Printed in Great Britain
by S. Jahanmir
The use of engineering ceramics in practical tribological applications has increased rapidly over the past decade, and although there are severa: books covering the general topic of mechanical behaviour , there is a real need for an authoritative and up-to-date treatment of the trlbological behaviour of this important class of materials. The title of this edited volume suggests that it might fill that need, and the publisher promises on the back cover that ‘this practical, single source volume provides comprehensive information for all uses that require controlled friction and wear resistance and serves as a guide for altering the microstructure of ceramics to create optimal performance II sliding and rolling contact applications’. The book contains 16 chapters, by a total of 29 contributors, all from the USA. It offers a combination of valuable reviews (constituting about half the book) on various aspects of the tribology of ceramics, and a snapshot, interspersed between the reviews, of selected recent research work from the US on more closely-focused topics. All chapters are accompanied by comprehensive lists of references. The book is well produced and typeset to a hgh and uniform standard. It is dil;ided into three main sections of five chapters each, covering the fundamentals of friction and wear, solid lubrication and composites, and tribological applications. The reviews start with a good but brief isurvey by Jahanmir of the main classes of bulk engineering ceramics, together with some tribological applications; no mention of diamond is here, however, nor of ceramic matrix composites, and Marcel Dekker, pp 429.
only very scant reference to thin coatings. Fischer and Mullins next contribute an all too brief review on the influence ‘of surface chemistry on tribological behaviour, which includes some provocative discussion of the effect of electronic structure and concludes with enthusiastic comments on the need for further research in this area. Tribochemical effects are also mentioned by several other contributors, and deserve full attention in any tribological study of ceramics. In his discussion of abrasive wear, Larsen-Basse is unavoidably hampered by limited data, but makes the important point that most practical cases of abrasive wear for ceramics will occur in the ‘soft’ abrasion regime, which is rather less well understood than the more commonly studied ‘hard’ regime, encountered for example with metals. The important topic of solid lubrication is well treated by Erdemir, with emphasis on the author’s own studies, especially of lubrication by boric acid and silver films; striking results are presented for the effect of ion-beam assisted deposition processes on metallic film adhesion and on the resulting lubrication performance. Liquid and vapour phase lubrication of ceramics do not, however, feature in the book. Yust presents a knowledgeable review of the complex effects of whisker-reinforcement and transformation toughening on tribological performance. He shows that improvements in conventionallymeasured mechanical properties such as fracture toughness, although readily achieved, may well for a variety of reasons not lead to decreased wear rate. The final section of the book, on applications, contains four fine reviews. Komanduri discusses in broad terms the material requirements for cutting tools and the use Tribology
of ceramics for this application. Rolling bearings constitute another important use for ceramics, and the chapter by Katz discusses the impressive state of development currently attained in this area, especially with silicon nitride. A good review of ceramics for face seals, by Divakar, covers selection criteria and failure mechanisms and discusses the range of materials used for this type of machine element. The final contribution in the book is a discussion of ceramics for magnetic recording applications, by Chandrasekhar and colleagues, which contains an excellent review of a wide range of ceramic materials, their synthesis routes and properties, and is of much more general interest than its title might imply. The contributions which make up the rest of the volume are considerably more specialized than the review chapters, and in many cases are papers on quite narrow research topics, of the kind published in journals or conference proceedings. They complement the more general reviews, but are likely to be of interest to a smaller range of readers. In some cases they concentrate on a narrow range of materials (e.g. pure polycrystalline alumina, or silicon carbide whisker-reinforced alumina), or focus on a particular specialized application (e.g. particulate-reinforced silicon nitride cutting tools, or cam roller followers for IC engines). However, the broad-minded reader will undoubtedly find a good deal of interest here, and will be able to relate many of the results to other ceramic systems or to other classes of application. Given the structure of the book and the number of different authors involved, it is probably inevitable that there will be some unevenness of quality in the chapters and some
duplication of basic information on ceramic properties, fabrication routes and microstructure. Some of the best coverage of the latter information, which might be expected close to the beginning of the book, is in fact in the final chapter. This is not a textbook
of ceramic tribology, nor is it a straightforward source of reference. It would not be easy to adopt for class use except at a very advanced level. As a collection of review articles, supplemented by more specialized papers, it will however undoubtedly be of significant value
to the researcher or development engineer working with ceramic materials, and is one of the very few recent collections of information in this important and burgeoning area. Ian Hutchings Cambridge, UK