A NETWORK MODEL FOR INITIAL-STAGE SINTERING

Densification of powders by initial stage sintering has been investiga ted through computer simulations. In the simulations, every particle c enter is represented by a node and every contact between neighboring p articles by a discrete element. The velocity of each node is related t o applied and sintering forces arising from the deformation mechanisms which are physically active. These processes are controlled by grain boundary and surface diffusion and determine the constitutive laws for the behavior of each discrete element. The contribution of each discr ete element is then assembled into a system of equations that represen t the behavior of the powder system network. Solution of these equatio ns provides predictions of the motion of particles during sintering. T he results are used to characterize the free sintering of metal powder s as well as stress assisted sintering. (C) 1998 Elsevier Science Ltd.