Computer simulation of the influence of grain-boundary mobility on grain growth

Grain-boundary mobility, which plays a significant role during grain growth in polycrystalline materials, is related to activation energy for grain-boundary migration. From this aspect, the authors simulated grain growth considering mobility into an activated state accompanying reorientation. The mobility is affected by impurities in the activation process and is represented as a function of interaction factor between grain boundary and impurities. The authors confirmed that grain boundary migration is slower for a larger interaction factor. Assuming a constant driving pressure of the grain boundary, the mobility suggests Arrhenius type dependence of temperature. The direction of grain-boundary migration at a triple junction depends on not only the grain boundary energy but also the interaction factor. Therefore, equilibrium at the triple junction of grain boundaries should be established based on the grain-boundary energy compensated by the mobility.