540 Phase Field 法による多結晶金属の結晶粒成長シミュレーション

Abstract

Grain growth process of polycrystalline metals which comprises of grain boundary migration and rotation of crystal orientation has been clarified by employing Phase Field Method. The strain energy stored due to the plastic deformation of polycrystal is evaluated by the crystal plasticity theory and approximately introduced to the free energy. The effects of such factors as strain energy, misorientation between grains, and curvature of grain boundary on the grain growth process have been clarified. The large misorientation between grains causes dominant migration of grain boundary, while the small misorientation causes dominant rotation of crystal orientation. The larger the magnitude of strain energy yields the faster grain growth. The changing rate of the area of grain boundary is preserved during the grain growth process. The rate of grain boundary migration depends on misorientation, and is proportional to the curvature of grain boundary.