Modeling length scale effects on strain induced grain boundary migration via bridging phase field and crystal plasticity methods

Abstract

A coupled crystal plasticity and phase field modeling framework is employed to simulate polycrystalline grain growth via static strain induced grain boundary migration. Specifically, the effect of the average grain size as a microstructural length scale on the development of microstructure and texture in columnar–grained aluminum polycrystal is examined. During annealing, subsequent to plastic tensile straining, a nearly normal grain growth regime is observed for comparatively small microstructural length scales. However, for comparatively large microstructural length scales, abnormal grain growth and development of a specific texture emerge. Hence, grain growth is found to transition from normal to abnormal by enlarging the microstructural length scale. These observations are attributed to the fact that the competing driving forces for grain boundary migration scale differently with the microstructural length scale. In addition, for the case of large microstructural length scale, a transition from abnormal to normal grain growth at later annealing times is observed. This observation is attributed to the weakening of the strain induced boundary migration effects due to the initial rapid reduction of dislocation content.