Pore channel closure in sintering of a ring of three spheres

Three-dimensional numerical simulation of sintering of a ring of three spheres was performed to investigate the effect of the ratio of grain boundary energy γgb to surface energy γs, or dihedral angle, to the nature of pore channel closure. As the ring shrank, the hole at the center closed to form a triple junction. The force acting between particles, that was the sintering force, was defined by including both surface tension and grain boundary tension. The shrinkage rate was approximately proportional to the sintering force, but became non-linear at lower γgb/γs. The sintering force, and also, shrinkage rate increased with decreasing γgb/γs, then, the hole closed in a short time at low γgb/γs.