Effect of Ce, Sm and Sr micro-alloying on the microstructure, mechanical properties and anisotropy of rotated rolled Mg–4.5Al–1.5Sn–0.5Ca–0.2Mn alloy

Mg-Al series sheets usually exhibit an apparent mechanical anisotropy induced by strong basal texture. In this study, a near-isotropic Mg-4.5Al-1.5Sn-0.5Ca-0.2Mn (ATXM5210) alloy was developed via 0.05 wt.% Sr micro-alloying combined with rotated rolling, displaying an ultra-low difference in yield strength (∼5 MPa), ultimate tensile strength (∼2 MPa) and elongation (∼1%) between the rolling direction (RD) and transverse direction (TD), in contrast to a strong anisotropy of Sr-free alloy. We comparatively investigated the effect of trace Ce, Sm and Sr addition on the microstructure, texture evolution and mechanical properties of rolled ATXM5210 alloy. Specially, Sr-containing alloy possesses a more uniform distribution of finer CaMgSn particles after rolling, whereas coarse particles and particle bands are still distinctive in Sr-free alloys. Furthermore, the addition of Sr contributes to form broader-distributed texture towards both RD and TD with reduced peak intensity (∼10.8), leading to an apparently reduced mechanical anisotropy. It indicates that Sr addition could effectively minimize the influence of loading directions on mechanical properties. The quite low mechanical anisotropy and balanced combination of yield strength (∼220 MPa) and ductility (∼21%) make the present ATXM5210-0.05Sr alloy suitable for producing intermediate or final products and competitive for various engineering applications.