A Potts Model parameter study of particle size, Monte Carlo temperature, and “Particle-Assisted Abnormal Grain Growth”

Abstract

Grain growth kinetics are known to deviate from the classical n = 2 behavior when particles in the microstructure impede grain boundary motion, and eventually halt as the driving force of grain boundary curvature approaches the pinning force exerted by the particles. Potts Model simulations were evaluated with respect to the non-physical Monte Carlo simulation temperature and theoretical predictions of grain growth behavior in the presence of second-phase particles. These simulations demonstrate that by modifying the simulation temperature, the pinned grain size will follow a selected inverse-linear relationship with respect to particle volume fraction. From these results, we suggest an approach for selecting Potts Model simulation temperature. Additionally, parameterizations of particle size, volume fraction, and simulation temperature in which the previously observed simulation phenomenon “Particle-Assisted Abnormal Grain Growth” (PA-AGG) occurred were recorded and discussed. The majority of this grain growth behavior occurred for simulation temperatures TS ≥ 1.5, particle diameters of less than six cells, and particle volume fractions smaller than 10%. However, PA-AGG was also observed in simulation for particle diameters of up to ten cells, particle volume fractions of twenty percent, and simulation temperatures as small as TS = 0.5. An analysis of the simulated grain size distributions showed that the occurrence of PA-AGG was not dependent on the abnormal grain reaching a critical relative grain size. The simulation domain size does not appear to have an influence on this effect.