07/29/2005 -
Corrosion of Ceramic and Composite Materials, Second Edition (2004)
by Ronald A. McCauley
ISBN 0-8247-5366-6. Marcel Dekker, New York. 2004. Hardcover. 405 pages. $99.95.
| REVIEWED BY: |
Kevin Plucknett, Dalhousie University
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When we think of ceramic materials, corrosion is not generally the first problem that comes to mind. They are often brittle and expensive to manufacture, but most would view them as being relatively inert materials. As Corrosion of Ceramic and Composite Materials by Ronald A. McCauley demonstrates, the reality is that in a great many situations ceramics do corrode. In fact, it is often the favorable properties of these materials that lead to their use in aggressive environments that promote corrosion phenomena.
There are few comprehensive information sources available to ceramists working in the field of corrosion and oxidation, being largely limited to conference proceedings and journal articles. Consequently, Corrosion of Ceramic and Composite Materials is a welcome addition to the literature in this important area. At approximately 400 pages, this volume is divided into nine chapters covering various aspects of corrosion of traditional and advanced ceramics, and their related composites, including materials with polymeric and metallic matrices.
After a brief introduction, the second chapter, "Fundamentals," deals with a variety of phenomena that occur during corrosion and contains a wealth of important concepts and information on corrosion mechanisms. The author covers a lot of fundamental ground in this chapter, ranging from corrosion mechanisms, through thermodynamics and kinetics, to diffusion. The basic types of corrosion reactions are described from the perspective of the material states (i.e., solid-liquid, solid-gas, etc.) as well as material type (i.e., glass or ceramic). There are points in this chapter where the author assumes a detailed level of background knowledge, which can mean occasionally looking to other fundamental chemistry and physics sources to clarify issues.
The third chapter deals with methods of corrosion assessment and, in many respects, is the most disappointing within this book. First, it is a somewhat misleading title, as I was anticipating a thorough treatment of techniques for assessing corrosion behavior, such as electrochemical impedance spectroscopy, thermogravimetric measurements, accelerated testing methods, burner rig testing, environment control, etc. Instead of this, the author has chosen to focus largely on techniques for assessing materials after corrosion, such as optical or scanning electron microscopy (SEM) and x-ray diffraction. Such information can easily be found in appropriate texts on these topics, so a briefer synopsis would have been better. In fact, the information given can be misleading, as it often appears to be out of date. For example, it is stated that optical microscopy is generally favored over SEM, as the latter method does not permit dynamic experiments to be conducted. This is not really true, as a wide variety of dynamic experiments are possible, particularly with environmental SEM, which allows the use of reactive gases as well as the option to condense water in-situ in the chamber.
Chapter four is essentially a brief summary of ASTM standards for corrosion testing that could easily have been left as an appendix. This is useful information, but concentrates primarily on traditional ceramic-based materials such as refractories, porcelain, glasses, and cements.
Much of the value of this volume lies in the content of the core chapters, five through nine, which focus on corrosion of specific material types, namely ceramics, glasses, and composites, and the effects of corrosion on properties. Each of these chapters provides a reasonable overview of the different corrosion responses that predominate for each class of material and the various subgroups that are defined primarily by composition, under a variety of conditions. While they could be more comprehensive, especially for researchers actively working on one or more of the individual materials, they do provide a good overview of the main issues. After touching on them in chapter two, it would be nice to see more coverage of biological and functional ceramics, such as fuel cell constituents; this is certainly an area to expand on for future editions. Similarly, two largely overlooked topics are cermets (ceramic-metal composites) and coatings. The former materials are often used in harsh environments, such as pulp and paper manufacture, while ceramic or cermet coatings are widely employed on metallic substrates for wear or corrosion protection, including the replacement of chrome plating. A final brief chapter deals with methods to reduce corrosion and largely focuses on compositional modification approaches. This could be improved with, in particular, protective coatings given greater attention.
In summary, Corrosion of Ceramic and Composite Materials is certainly a valuable, if slightly flawed, addition to the literature in this important area. It is suitable as a graduate-level text and will be of general use to researchers in the field of corrosion.
For more on this book, visit the CRC Press web site. |
