Abstract：The evolution of microstructure significantly influences the mechanical behaviors of magnesium alloys. To reveal the relation between the plastic anisotropy and the heterogeneous deformation by twinning for Mg alloys, the uniaxial tests with different loading paths were conducted, and the deformation behaviors of Mg alloys were simulated using the crystal plasticity constitutive model, which can nicely describe the different deformation mechanisms of slip, twinning and lattice rotation. A representative volume element of material with the microstructural parameters of grain size, crystal orientation and grain-boundary misorientation angle was adopted. The Mg alloy sheets exhibit considerable plastic anisotropy. The comparison shows excellent agreement between the predicted results and the experimental data of the plastic anisotropic behaviors and polycrystalline textures of Mg alloys. The analysis of heterogeneous deformation by twinning indicates that the plastic anisotropic behaviors of Mg alloys are closely related with different activated combinations of the slip and twinning mechanisms. The inhomogeneous stress distribution in polycrystalline is significantly affected by twinning. However, the deformations by twinning in different sizes of grains are quite different, which results in the inhomogeneous distribution of twinning variants in grains. This research contributes to the design and control of the mechanical properties of magnesium alloys through a further improvement in the microstructure.
2019, Vol. 40 
