Role of Surface Redistribution in Sintering by Grain Boundary Transport

Abstract

When a compact of particles densities- by grain boundary diffusion of matter from the boundaries between the particles, the matter entering the neck must redistribute itself over the neck surface. It is normally assumed that this redistribution is rapid, and that the rate of boundary diffusion limits the overall rate of densification. Under certain circumstances, however, the redistribution can be rate-limiting. An approximate model is developed for this coupled process, and the circumstances under which it is important are discussed.