Rigid body motion of multiple particles in solid-state sintering

The deep understanding of rigid body motion and shape change of multiple particles is required to predict the complicated microstructural evolution during sintering for manufacturing products with tailored properties. Although large-scale simulations of sintering, such as the phase field method, the kinetic Monte Carlo method, and the discrete element method, have been developed recently, it is still a challenge to incorporate the rigid body motion of particles correctly. Here we present a rigorous simulation of sintering by coupled grain boundary and surface diffusion to show how rigid body motion accelerates the fundamental processes in complex evolution of microstructure, e.g., the growth of contact area, the pinch-off of a pore channel, and the shrinkage and elimination of a closed pore. We propose that this result will be used as a benchmark for checking to what extent large-scale multi-particles simulations can approximate the rigid body motion of particles in sintering accurately.