Simulation of thin film grain structures—II. Abnormal grain growth

Abstract

A computer simulation of grain growth in two dimensions has been used to model microstructural evolution in thin films. In a companion paper we have simulated the stagnation of grain-growth due to grain-boundary grooving at the free surface of the film. In this paper we model the effect of driving force variations (due to variations of the free-surface energy among different crystals) on the origination and propagation of abnormal or secondary grain growth. The simulation produces an estimate for the magnitude of the driving force which is required to produce abnormal grain growth. The simulation also indicates that a key requirement for classic abnormal grain growth behavior is that a majority of the grains have free-surface energies which differ very little from each other.