α-Tiの繰返し負荷時におけるひずみの再分配とすべり系の活動度変化の結晶塑性解析

抄録

We conducted crystal plasticity analysis of a bicrystal model using a crystal plasticity finite element method (CPFEM), and the activities of slips systems in the α-phase of Ti-6Al-4V alloys (Ti-64) under cyclic loading were investigated. The crystal orientations were set such that prismatic <a> and basal slip systems were the primary slip systems in the crystal grains, respectively. The results showed that the occurrence of work hardening in a crystal grain decreased the volume of deformation and increased those of elasto-plastic deformations in neighboring crystal grains. The phenomenon leads to activation of slip systems in neighboring crystal grains. Thus, although the prismatic <a> slips initially operates under a cyclic loading, the basal slip system in the neighboring crystal grains displays a potential for activation by work hardening on the prismatic <a> slip system. The mechanism of changes in activities of slip systems by the interaction between crystal grains can be explained by the wedge disclination-type deformation field.