Development of a DEM taking account of neck increments caused by surface diffusion for sintering and application to analysis of the initial stage of sintering

Abstract

A discrete element model (DEM) capable of handling changing temperatures was newly developed for simulating sintering phenomena. The neck growth rate caused by surface diffusion was determined using a finite-difference model (FDM). The developed DEM was applied to clarify the effects of surface diffusion on the shrinkage behavior. The simulation results indicated that surface diffusion suppressed the local shrinkage through neck growth; on the other hand, the simulation excluding surface diffusion showed rapid local shrinkage. As a result, some cavities were enlarged when surface diffusion was not taken into consideration. It is known that surface diffusion reduces the driving force for shrinkage; however, it was revealed that surface diffusion has advantages in restricting the growth of inhomogeneity during the initial stage of sintering, which was expected to reduce pores at the end of sintering.