Effect of tensile direction on mechanical properties and microstructural evolutions of rolled Mg-Al-Zn-Sn magnesium alloy sheets at room and elevated temperatures

In the present work, Mg-9Al-1Zn-0.4Sn (AZT910) magnesium alloy sheets with a fine-grained structure (∼5 μm) and tilting basal texture were prepared by a 16-passes rolling process. Effect of tensile directions on properties and microstructural evolutions of the AZT910 alloy sheet at different temperatures, i.e. room temperature, 200 and 300 °C, respectively, were investigated by using three kinds of tensile specimens (rolling direction (RD), transverse direction (TD) and 45° towards RD). Experimental results showed that tensile properties exhibited a strong dependence on tensile directions at room temperature and 200 °C, while a negligible dependence at 300 °C. The anisotropic tensile properties imply that the deformation system of rolled AZT910 sheet consists of basal and non-basal slips at room temperature, and is a combination of basal slip, non-basal slip and grain boundary sliding/rotation (GBS) at 200 °C. The decrease of intensity and spreading of basal poles during tensile test and isotropic tensile properties indicates that GBS becomes the dominate deformation mechanism at 300 °C. The present work provides reference for the study of deformation behavior of novel superplastic magnesium alloy, and hence is of great significance for further application of wrought magnesium alloy. •Tensile properties exhibit anisotropy at RT and 200 °C and isotropy at 300 °C.•The deformation system of rolled AZT910 consists of basal and non-basal slips at RT.•The deformation system consists of basal slip, non-basal slip and GBS at 200 °C.•GBS is the dominate deformation mechanism of rolled AZT910 at 300 °C.