Micromechanisms of Grain-Boundary Recovery upon Annealing after Deformation: I. Recovery of Diffusional Properties of Grain Boundaries

摘要

A model is suggested that describes the experimentally observed changes in the energy of activation for grain-boundary diffusion in fine-grained polycrystalline metals upon annealing after deformation. The model is based on the theory of nonequilibrium grain boundaries developed in previous authors' papers. In this paper, it is shown that the changes in the characteristics of grain-boundary diffusion in fine-grained materials are related to the "escape" from grain boundaries of defects that were introduced into the boundaries during a preliminary deformation. Equations are derived that make it possible to describe the dependence of the diffusion characteristics of the boundaries on the time and temperature of annealing, as well as on the structural parameters of the materials.