Microstructure and mechanical properties of severely deformed Mg-4.5Al-1.0Zn alloy processed by asymmetric rolling on ingot and twin roll cast strip

Abstract

The twin roll cast Mg-4.5Al-1.0Zn alloy sheets, processed by asymmetric rolling and subsequent annealing were investigated. The asymmetric rolling on Mg-4.5Al-1.0Zn ingot was also studied for comparison in terms of microstructure, texture and mechanical properties of the sheets. The results can be summarized as follows. The rolled sheets show intensively deformed band structures and fine grains due to dynamic recrystallization. After annealing at 375 °C for 1 hr, both the twin roll casted and ingot processed sheets show the fine equiaxed grains with around 9 ìm in mean diameter. The twin roll casted magnesium alloy sheet shows superior tensile strength and low elongation compared to the ingot cast one. The results of this work suggest that asymmetric rolling can improve the formability of magnesium alloy and the technique could be extended to enhance the sheet qualities of different alloys in jewelry industry.