The microstructural mechanism of the strength differential effect in polycrystalline pure magnesium with rolling texture was numerically investigated by rate-dependent crystal plasticity finite element analysis. The present analysis method considers basal slip, prismatic slip, first-order pyramidal slip, and second-order pyramidal slip, as well as deformation twinning due to c-axis tension. Critical resolved shear stresses of single crystal pure magnesium reported in the literatures were used for the material parameters in the analysis. The strength differential effect in a numerically generated material, which has a strong texture typical of rolled magnesium, was examined by simulating tensile and compressive tests. The results show a significant strength differential effect due to deformation twinning. The results of simulations that do not take deformation twinning into account, however, still show a non-negligible strength differential effect. This persistent strength differential effect, which has no relation to the twinning, was explained in terms of lattice rotation and different critical resolved shear stresses on different slip systems.

Influence of Twinning Deformation and Lattice Rotation on Strength Differential Effect in Polycrystalline Pure Magnesium with Rolling Texture. T.Mayama, K.Aizawa, Y.Tadano, M.Kuroda: Computational Materials Science, 2009, 47[2], 448-55