マルチスケール結晶塑性有限要素法に基づくマグネシウム合金の塑性変形解析

抄録

To clarify the plastic deformation induced crystal texture evolution of rolled magnesium alloy sheets with strong basal texture, we developed a multi-scale finite element (FE) analysis code based on the homogenization theory, which combines the microscopic poly-crystal structure and the macroscopic continuum. In our crystal plasticity constitutive equation of magnesium alloys, the plastic work induced temperature rise and twinning in the crystal slip systems were implemented into our multiscale FE analysis code. To validate our numerical code to correctly predict macro- and microscopic deformations including the crystal texture evolution, the tension and compression along normal direction (ND) and rolling direction (RD) at the room temperature 300K and the high temperature 673K were numerically investigated. Then planar ND compression and the combination of planar ND compression and planar simple shear, which are respectively representing the middle and the surface layer of rolled plate, were also investigated. Although there are some points to be improved with regard to temperature dependency, it is confirmed that numerical results showed the similar tendency to experimentally obtained results including the strengthening the basal texuture in compression along ND, the twinning, the polarity of twinning and the temperaturedependency that twinning is hardly appear at high temperature. All the results obtained in the present study certify the potential of our numerical method in predicting the texture evolution as the process-metallurgy analysis tool for the practical application of magnesium alloy forming.