Grain Boundaries : Description , Structure

Abstract

This chapter briefly introduces geometric and thermodynamic description and atomic structure of the grain boundaries. The grain boundaries are classified from the points of view of their misorientation angle, relationship between the rotation axis and normal to the boundary plane and interfacial energy. With respect to the latter case, the boundaries are classified into general, singular (special) and vicinal. Simple geometric models for identifying the singular/special grain boundaries are also outlined. Finally, the basic thermodynamic variables related to the grain boundaries are introduced on the basis of Cahn approach.