Geometrical speciality and special properties of grain boundaries

2014 It has long been a major preoccupation of materials users, whether implied or explicit, to tailor microstructures in order to adapt specific properties for a given application. In this context, the principal aim of the present review article is to consider the fundamental elements of polycrystal microstructures, i.e. the grain boundaries. The paper discusses current understanding of two important aspects : a) the possible relationships between the geometry of a grain boundary, which determines its structure, and its various properties ; b) the distribution of geometrical characteristics, which for real boundaries can only be approached experimentally, in an endeavour to determine the intergranular contribution to the overall properties of a polycrystal. Revue Phys. Appl. 24 (1989) 419-438 AVRIL 1989,