Strong strain hardening ability in an as-cast Mg–3Sn–1Zn alloy

The plastic deformation behavior of as-cast Mg–3Sn–1Zn (TZ31) alloy was investigated at room temperature, which exhibits strong strain hardening ability (i.e. n=0.55 and Hc=3.62) and high elongation (εp=19.1%). The generalized stacking fault (GSF) energy of TZ31 alloy is reduced owing to dopings of Sn and Zn atoms, which is beneficial to improving activity of basal slip, activation of non-basal slips and formation of numerous deformation twins. The high density of twins significantly restricts dislocation motion, leading to strong strain hardening ability of the TZ31 alloy. Results obtained here will shed some light on deformation mechanisms of Mg–Sn–Zn alloys, critical to the development of new high-plastic magnesium alloys.

► As-cast Mg–3Sn–1Zn (TZ31) alloy exhibits a strong strain hardening ability.
► Dopings of Sn and Zn atoms reduce the GSF energy of TZ31 alloy.
► Reduced GSF energy is beneficial to facilitating activation of non-basal slips.
► Reduced GSF energy is beneficial to facilitating twinning during deformation.
► Dislocation accumulation leads to a strong strain hardening ability of TZ31 alloy.