The mechanism of densification during sintering of metallic particles

Abstract The possible mechanisms which may bring about shrinkage of pores during sintering are discussed, In view of the Alexander-Baluffi experiment, only two such mechanisms are possible: 1. (1) diffusion along grain boundaries, 2. (2) volume diffusion with sinks at grain boundaries (Nabarro-Herring microcreep). The excess vacancies are transmitted to the grain boundaries and through their network out of the compact. The probability of occurrence of these mechanisms is discussed. It is concluded that the volume-diffusion mechanism is the more probable one.