Texture and Mechanical Properties of Mg-3Al-1Zn-0.5Mn-1.5Ca Alloy Produced by Torsion Extrusion

Abstract

Torsion extrusion was carried out on Mg-3Al-1Zn-0.5Mn-1.5Ca (in mass%) alloy (AZ31+1.5Ca alloy). The annealed torsion-extruded AZ31+1.5Ca alloy exhibited higher elongation compared with the annealed extruded AZ31+1.5Ca alloy without torsion. The ductility enhancement was attributed to a unique texture with ⟨10\\bar10⟩ direction inclined 30° from the extrusion direction and low pole density. Besides, the annealed torsion-extruded AZ31+1.5Ca alloy exhibited higher strength compared with the annealed torsion-extruded Mg-3Al-1Zn-0.5Mn (in mass%) alloy (AZ31 alloy). In the extruded AZ31+1.5Ca alloy, the fine second phase particles, which contributed to a suppression of the grain growth during extrusion and annealing, were observed. The enhanced strength of the annealed torsion-extruded AZ31+1.5Ca alloy was likely attributed to not only grain refinement but also strengthening by the presence of the second phase particles.