Phase transformation of Mg-Li alloys induced by super-high pressure

The effect of superhigh pressure (4 GPa) on phase transformation behavior and mechanical properties of a duplex phase Mg-7 wt%Li alloy has been investigated in the temperature range from 450 to 1150 °C. Hardness and tensile strength of Mg-7 wt%Li alloy have been significantly improved by super-high pressure treatment at 700 °C for 120 min. The microstructural observation is confirmed that super-high pressure is of benefit for phase transformations from bcc-Li3Mg7 to hcp phases and hcp-Li3Mg17 to hcp-Li0.92Mg4.08. The improved mechanical properties are mainly associated with the reduction of bcc-Li3Mg7 phase and the formation of {1 0 −1 1} compression twins in hcp-Li0.92Mg4.08 phase.