Effects of Texture on Twin Propagation and Thickening in Magnesium Alloys

Twinning is the significant deformation mechanism in HCP metals and alloys. Due to its complex mechanisms, it is still not fully understood. Twinning spans several length scales within the microstructure, from the atomic level during initiation to the grain-scale during propagation and thickening. The twinning process significantly changes the stress and strain distribution within the microstructure by imposing lattice rotation and twin shear. Twinning analysis requires a multiscale modelling approach. The study presented here focuses on the grain-scale interaction of the propagating twin with the surrounding microstructure. The main focus is on the distribution of stresses and strains and their dependence on twins’ geometrical characteristics and crystallographic orientations of surrounding grains. The numerical analysis is performed using the finite element method within the framework of the crystal plasticity model for HCP materials. The twin is treated as an inclusion inside the microstructure, which undergoes internal shear strain transformation. The microstructural effects are evaluated by the stress that has to be applied in order to keep the system in equilibrium.