Twinning behaviors of Mg−Sn alloy with basal or prismatic Mg2Sn

The Mg−Sn alloys, with basal or prismatic Mg2Sn laths, were employed to reveal the effect of precipitate orientation on twinning behavior quantitatively. The Mg−5wt.%Sn alloys with basal or prismatic Mg2Sn were compressed to study the twinning behaviors. Subsequently, an Orowan strengthening model was developed to quantitatively investigate the critical resolved shear stress (CRSS) increment of precipitates on twinning. The results revealed that the prismatic precipitates hindered the transfer and growth of tensile twins more effectively compared with the basal precipitates. The decreased proportion of tensile twins containing prismatic Mg2Sn might be attributed to a larger CRSS increment for tensile twins compared with that for basal precipitates. The obvious decreased twinning transfer in the alloy with prismatic Mg2Sn could be due to its higher geometrically necessary dislocation and enhanced CRSS of tensile twins. Notably, the prismatic precipitates have a better hindering effect on tensile twins during compression.