Simulation of grain growth under simultaneous grain boundary migration and grain rotation using multi-order parameter phase-field model

Abstract

Study of microstructure evolution in the form of grain growth in polycrystalline materials has been an important goal for material scientists as it drastically affects physical and mechanical properties. Specifically, nanocrystalline materials, which are known for their superior mechanical properties, are highly susceptible to grain growth even at low temperatures and stresses. Various experiments and simulations carried out on nanocrystalline materials indicate that the microstructure evolution in these materials takes place due to grain boundary migration and grain rotation. Therefore, migration of grain boundaries and grain rotation-induced grain coalescence contribute in increasing the average grain size in the microstructure. In order to simulate microstructure evolution in polycrystalline materials, the multi-order parameter phase-field model is a popular approach and is widely used for studying evolution purely due to the grain boundary migration. In this work, we present a multi-order parameter phase-field model capable of capturing microstructure evolution due to grain boundary migration and grain rotation-induced grain coalescence. The model couples constitutive equation of viscous sliding-induced grain rotation and the classical phase-field model for curvature-driven grain boundary migration. This paper covers various topological and statistical aspects of the microstructure evolved in the presence of both these growth mechanisms in great detail.