Effect of extrusion conditions on microstructure and mechanical properties of microalloyed Mg-Sn-Al-Zn alloys

Newly developed TAZ1031 and TAZ1031-0.1Na alloys were extruded at different temperatures and extrusion speeds, and the resulting microstructure, texture, and mechanical properties were evaluated comparing to those of AZ31 alloy extruded with the same conditions. Tensile yield strength of TAZ1031 ranged from 214 to 319 MPa with elongations of 6-15% depending on extrusion conditions. The TAZ1031-0.1Na alloy exhibited even higher yield strength of ~336 MPa at the expense of ductility. The alloys were found to show good yield anisotropy of ~1 when extruded at 250 °C. The high strength is attributed to the fine grain size as a result of the recrystallization accompanied by dynamic precipitation.