Diffusion decomposition of nanocrystalline alloys at generation of non-equilibrium vacancies on grain boundaries

Abstract

The problem of formation of decomposition zone in nanograin under generation of non-equilibrium vacancies from boundaries, when volume sinks for them are absent has been solved. Two space-time scales characterizing the anomalous diffusion of components responsible for the occurrence of comparatively narrow adjacent boundary region with changed concentration and the process of diffusion of vacancies proper expanding to distances that are significantly far away from the boundary, respectively, have been revealed. The peculiarities of spatial distribution of concentration inhomogeneity near boundary have been analyzed.