Abstract
When a huge number of particles is in mutual contact at elevated temperatures, the evolutionary formation of grain boundary network and the morphological change of pore channels take place in the process of sintering. While the complicated morphological change of interfaces occurs microscopically, the sintering is macroscopicaly described as the densification, i.e., the increase of bulk density by the decrease of pore volume. In the macroscopic continuum theory of sintering the shrinkage rate of porous material is expressed as a response to the external stress and the driving force of sintering, i.e., sintering stress. Here we propose an exact method to determine the sintering stress tensor of porous materials from the interfacial energies of pores and grain boundaries. This method is applicable to calculate the sintering stress of materials with anisotropic complex microstructures in non-equilibrium state. The realistic simulation of sintering of particles in three dimensions will be demonstrated.
