Twinning behavior and deformation mechanisms of extruded AZ31 Mg alloy

Complicated deformation mechanisms such as twinning, non-basal slips and grain boundary sliding besides the basal slip occur at room temperature for Mg and its alloys. The roles of these mechanisms should be understood from the viewpoint of the homogeneous deformation of a polycrystalline and the relaxation of stress concentrations at the grain boundaries. In the present paper, twinning behavior of AZ31 Mg alloy extrusions with different texture intensity and grain sizes was investigated. Twinning played a vital role in a coarse-grained Mg, not in a fine-grained Mg. Thus, the deformation behavior was drastically changed by grain refinement. Based on the results, the deformation mechanisms are discussed from the viewpoint of the deformation and relaxation mechanisms.