Design of dual-textured Mg-6.5Zn alloys with low tension–compression asymmetry by means of crystal plasticity simulations

The stress–strain curves and the deformation mechanisms of a dual-textured Mg alloy along the extrusion direction were studied in tension and in compression by means of crystal plasticity finite element simulations of a three-dimensional representative volume element of the microstructure. Some of the grains in the alloy presented the standard texture of wrought Mg alloys, while the grain orientation was rotated by ≈ 90 ° in the remaining grains. The simulations were able to reproduce the experimental stress–strain curves as well as the deformation mechanisms of the dual-textured alloy, which showed very limited tension/compression asymmetry in the yield strength. It was found that including the effect of re-slip in the twinned regions is very important to simulate the strain hardening of Mg alloys after most of the matrix has undergone twinning. In addition, the simulations were used to design an optimum microstructure with a dual texture made up of 29% of C-textured grains and 71% of E-textured grains that exhibits the same yield strength in tension and in compression and small differences in the strain hardening rates afterwards. These results demonstrated the potential of heterogeneous microstructures to overcome the limitations in the mechanical behavior of hexagonal metals imposed by limited numbers of available slip systems and the strong texture induced during thermo-mechanical processing.