Phase Boundaries, Particles, and Pores

Abstract

This chapter is both an extension of the chapters on surfaces and grain boundaries (GBs) and essential preparation for those on sintering and phase transformations. The theme of the chapter could be reworded as interfaces between ceramics and different materials; the material can be crystalline, amorphous (glassy), liquid, or gaseous (pore). Hence the topics include three critical areas for ceramics: phase boundaries (PBs), particles, and pores. Examples of PBs include ceramic/metal interfaces, crystal/crystal interfaces, and crystal/glass interfaces. Because we also include any interfaces that interact with pores it is a very large and important topic. By definition, PBs are the essential feature of composite materials. Solid-state reactions and reactions involving liquids and gases all occur by the movement of these interfaces, but the details of how this motion occurs are often even less well understood than the interfaces themselves.