The Structure Of Interphase Boundaries In Solids

Abstract

SUMMARYAlthough, in principle, the structure of solid interphase interfaces should be no different from those of regular grain boundaries in homophase materials, it is shown that special boundaries characterized by a high degree of order occur much more frequently in interphase boundaries than in homophase boundaries. This is mainly caused by the fact that complex phases are usually produced at the end of the processing history of a material. Thus precipitates, eutectics, the products of spinodal decomposition, martensites, surface precipitates, epitaxially‐deposited heterojunctions and similar materials all tend to have special boundaries. On the other hand, multiphase materials subject to the same kinds of thermo‐mechanical processing as homophase materials, e.g. duplex steels, alloys with grain boundary precipitates, and superplastically deformed materials, possess interphase boundaries closely akin to those of homophase materials. The origins and structural details of the different kinds of boundaries are explored.