Mechanics of sintering for coupled grain boundary and surface diffusion

Sintering by coupled grain boundary and surface diffusion was analyzed in terms of mechanics. The shrinkage is a result of the relative motion of particles caused by grain boundary diffusion. The center of mass of a particle also moves due to spheroidization of the particles by surface diffusion. The mobility and sintering force for both processes were calculated during sintering of two identical particles until they reached equilibrium. The contribution of grain boundary diffusion to the final shrinkage increased with increasing ratio of grain boundary diffusion coefficient to surface diffusion coefficient and the ratio of grain boundary energy to surface energy.