Computer simulation of grain growth with second phase particle pinning

Abstract

The pinning effect of second phase particles on grain growth was simulated by 2-D Monte Carlo simulations. A new variable, the degree of contact between grain boundaries and second phase particles, was introduced to predict the grain size limit in the presence of second phase particles. The modified Zener pinning model containing this new variable can be expressed as: D r = K Rf , where D is the pinned grain size, r is the mean size of second phase particles, K is a constant, f is the area fraction (or the volume fraction in 3-D) of second phase, and R is the degree of contact between grain boundaries and second phase particles. In 2-D Monte Carlo simulations of grain growth the ratio of pinned grain size to second phase particle size was found to be proportional to f −0.5, but also to ( Rf) −1. The degree of contact increased during grain growth and reached a stable value when the grain structure was pinned. The initial location of second phase particles did not have a significant contribution to the pinning of grain boundaries.