Computer modeling and simulation of solid-state sintering: A phase field approach

A phase field model of solid-state sintering is developed. The model treats multiple concurrent physical processes, i.e., rigid-body translation and rotation of powder particles, grain growth through boundary migration, and various diffusion mechanisms including surface diffusion, grain boundary diffusion, volume diffusion, and vapor transport through evaporation and condensation. The approach of centers of particles through rigid-body motions plays a key role in the densification of sintered powder compacts. The effective treatment of particle translation and rotation in phase field formalism is a necessary and critical step in developing a phase field sintering model. A scheme of particle translation and rotation is formulated based on a new formula of grain boundary force. The rigid-body motion modifies both the Cahn–Hilliard nonlinear diffusion equation and the Ginzburg–Landau (Allen–Cahn) structural relaxation equation by introducing advection terms. Computer simulations are presented.