Edited by By P. E. J. Flewitt and R. K. Wild, ed. John Wiley Ltd., Chichester, UK, 2001.
ISBN 0-471-97951-1
Reviewed by: Dr Paulo Piccardo, University of Genoa, Italy
Published in Microscopy & Analysis, May 2002
Materials science needs a microscopic, if not a nanoscopic knowledge in order to correctly understand and improve the properties of engineering materials. Most of the mechanical, physical and chemical properties of inorganic materials are directly influenced by their microstructure (i.e. size, shape, and orientation of grains and phases composing the bulk) and this fact is strongly affected by the atomic composition and distribution. For materials composed of grains it is obviously of primary importance to know the zone of bonding of these grains, i.e. the grain boundaries. This has been a must since the beginning of the last century. Thanks to the development of investigation techniques characterising this period a dramatic quantity of data concerning grain boundaries and their chemistry as well as their links to macroscopic properties has been collected and elaborated.
This book rises from a thorough overview of all the literature produced on this topic. It leads the reader through a fascinating and extremely interesting journey where all aspects are clearly explained and exemplified. The instances given are particularly important for those working on materials science as the book offers a concrete understanding of phenomena and stimulates reflections on personal experimental cases. The focus is on metals and alloys, however, other materials like the most important types of ceramics and also glasses are also discussed.
The book contains well-balanced chapters. Chapter 1 gives a background introducing the concept of grain, grain boundaries and surfaces with the correspondent underlying theories. This approach is common to the entire book, satisfying both the practical and the ‘theoretical’ reader. Chapter 2 discusses Grain Boundary Composition, also introducing the segregation mechanisms from both thermodynamic and kinetic points of view. This is preparatory to Chapter 3 which focuses on Composition Changes in Materials. Here are widely treated the processes acting on the composition of grain boundaries, interfaces and interphases boundaries. Properties of grain boundaries are strongly affected by their composition and materials properties can drastically change in function of that. It is then important to understand the reasons and driving forces that determine these processes as this will improve material characteristics.
Chapter 4 presents all the investigation methods available at the present time, discusses their pros and cons, presents the theory (mainly for the latest techniques, e.g. STEM or EELS), and always enriches the presentation with practical examples. Chapter 5 is dedicated to mechanical properties and how grain boundaries, surfaces and their changes may affect them. The authors here finalise the path built step-by-step in the book where the right instruments to a complete understanding of the influence of grain boundaries on engineering materials now in use are made available to the reader. Great importance is paid to fracture and failure, showing how simple and small changes in boundaries may result in dramatic alterations of mechanical properties. All discussions previously presented about practices affecting segregation (e.g. either thermal treatments or radiation or environmental chemical etchings) are, in this chapter, fundamental arguments that help to understand why similar materials may have different behaviours. Creep, which represents a questionable mechanical property of undeniable technological importance strongly influenced by grain size, is deeply treated and the role of grain boundaries characteristics and composition is widely explained.
A complete reference list follows and enriches all the chapters allowing and stimulating the reader to use it as a starting point to carry on wider researches on these topics. This is a valuable and remarkable work. People working on, researching, teaching and then studying materials science will find this book indispensable both as a ‘tutor’ and as a reference for further developments on the subject.