Atomic Structure of Grain Boundaries and Intergranular Segregation

— Some Important aspects of the atomic structure of grain boundaries in pure metals, in particular the structural model of general grain boundaries and the multiplicity of structures, are discussed first. An empirical scheme for the desciption of atomic interactions in alloys is then outlined. General, structure independent, properties of segregation are examined in the framework of this scheme. Results of the atomistic calculations of grain boundaries with a low as well as a gradually increasing concentration of impurities are then presented. The relationship between the boundary structure and the propensity to segregation together with the structural changes invoked by segregation, are discussed in the light of these calculations.