The sintering of two particles by surface and grain boundary diffusion—a two-dimensional numerical study

We investigate the sintering of two touching circular particles by surface and grain boundary diffusion. Typical examples for the evolution of the shape of the particles, their surface curvatures, and their surface fluxes are given. The sintering kinetics are evaluated as a function of the dihedral angle at the grain boundary-surface junctions and the grain boundary to surface diffusivity ratio. In particular, the growth rates of the neck between the two particles, the growth rate exponents, and the changes in the lengths of the particle pairs are monitored. The times needed to reach certain fractions of the final equilibrium neck sizes are tabulated for typical experimental dihedral angles and diffusivity ratios. Our simulation is based on a rigorous mathematical system modeling the sintering of the two particles, and a rigorous numerical method for solving this system is adopted.