Analyses of grain growth behavior in particle-dispersed materials by finite element simulation

The grain growth behavior in particle-dispersed materials is investigated by using finite element simulation on the interaction between a curved grain boundary and a spherical particle. By varying the radius of the grain boundary curvature and the particle size, quantitative analyses on the relationship between particle dispersion and mean critical grain size, and between particle dispersion and grain growth rate are carried out. The effect of migration velocity of the grain boundary during the interaction is taken into account in the present analyses. The pinning stress by dispersed particles increases with increasing radius of the grain boundary curvature, and the increasing rate is accelerated as the mean critical radius of curvature is approached. The trapping condition of the grain boundary is evaluated for both cases of a single particle and uniformly distributed particles. The critical grain size is proportional to f(-2/3) for low f and is proportional to f(-0.7) for f approximate to 0.1, where f is the volume fraction of particles. The power law for grain growth is obtained in particle-dispersed materials for f less than or equal to 0.15, and the grain growth exponent is shown to vary with 2 + f(0.38).