Deformation Behavior of Magnesium Alloys under Multi-axial Stress States

Recently, magnesium (Mg) has been increasingly interest from the engineering viewpoint, because of its low density and relatively high specific strength. In this study, we carried out molecular dynamics (MD) simulations of the atomistic Erichsen testing to investigate nucleation and motion of defects under equibiaxial tension. For the surface orientation of (0001), the basal slip hardly occurred and alternatively the {1011} twins were generated. On the other hand, in the case of the (1011) surface orientation, the basal dislocations were generated, which reduced stress at the stretch forming region. Applying a simple L-J potential for interaction between Mg and an alloying element, we also evaluate effects of the doping on the deformation behavior under the Erichsen testing. In the Mg alloy models, the doped alloying element atoms suppressed growth of the {1011} twins and homogeneous deformation was maintained.