DEFORMATION OF INTERPARTICLE NECKS BY DIFFUSION-CONTROLLED CREEP

The deformation of a neck between two spherical particles of the same size by coupled grain-boundary and surface diffusion has been simulate d numerically through the finite-difference method, In the case of pur e sintering where there is no applied stress, the results agree quite well with simple analytical models. When a force is applied, it is fou nd that they do not deform as truncated spheres, even when surface dif fusion is much faster than grain-boundary diffusion, Expressions are g iven representing the rate of approach of the particles and the rate o f growth of the neck as a function of the current neck radius and the applied stress.