Selection Behavior of {10-12} Tensile Twin Variants and its Contribution During Plastic Processing of Magnesium Alloy

Prefabricated {10-12} tensile twins are an effective means to weaken the basal texture and strengthen the plastic processing ability of magnesium alloys. Successfully prefabricated {10-12} tensile twins in the magnesium alloy sheet by bending straightening and thickening, combined with the grain orientation distribution in {10-12} pole figure and self-made MATLAB code to identify the activated twin variants and explore the selection behavior of twin variants and use in-grain misorientation axis (IGMA) analysis to judge the slip system that matches it. The results show that the twins in the parallel relationship in the same matrix grains are the same twin variants and the twins that are at a certain angle are the parasite variants. Whether the selection behavior of twin variants conforms to Schmidt's law is determined by the local strain field at the position of the twins rather than the matrix grains. The degree of strain compatibility between twins will change the result of the twin variants selection caused by the strain field. The shear caused by low Schmidt factor twins is better adapted to the deformation system of its neighboring grains, which leads to non-Schmidt behavior in the selection of twin variants with uniform local strain distribution. The main contribution of twinning to plastic deformation is not the coordination of deformation, but the orientation of the matrix grains can be deflected in the direction that is easy to start the Pyramidal II slip