In recent years microstructural analysis has been a rapidly changing field of scien tific endeavor. No longer are the efforts of the microstructural analysts (sometimes referred to as metallographers, materialographers, ceramographers, and similar desig nations) limited to the tasks of polishing, etching, and photographing specimens of materials. The performance demanded of materials used for many current applica tions requires much more complete characterizations than were possible only a scant few years ago. Although the individuals who have been expected to develop new and improved techniques to permit these required characterizations have been severely challenged, in large part they have met the challenge. In view of the many new developments in the field of microstructural analysis and recognizing the requirements to communicate these developments to the wide audience that might make use of them, the American Society for Metals and the In ternational Metallographic Society joined forces to co-sponsor a symposium that was intended to bring participants and attendees up to date on the subject "Inter pretive Techniques for Microstructural Analysis". This symposium was held in Min neapolis, Minnesota, USA, June 29 and 30, 1975. It followed two earlier symposia co-sponsored by the same two societies on other subjects of current interest to the metallographic community, Microstructural Analysis - Tools and Techniques, 1972, and Metallographic Specimen Preparation - Optical and Electron Micros copy, 1973.

/.letallography is much more than taking striking pictures at high magnifications or polishing and etching specimens in such a way that no scratches can be seen. Basically, metallography is the physical metallurgist's most useful and most used tool for studying metals. Although it is perhaps his oldest tool, it certainly is not likely to become obsolete. Rather, the continued demands that have been placed upon materials have required more detailed charac terizations of their microstructures and this, in turn, has re quired the metallographer to develop new techniques to make these characterizations. Not too many years ago, the metallographer had only optical microscopes with which to examine his specimens. Now he has elec tron microscopes, scanning electron microscopes, and a whole host of instruments which were unknown to him only a relatively few years ago. This has forced him to learn not only how to use these new instruments and how to interpret the information that they provide but it also has made him develop new techniques for preparing the samples for examination.