Microstructure and mechanical properties of Mg–6Li– x Al–0.8Sn alloys

As-cast and as-extruded Mg–6Li– xAl–0.8Sn ( x = 0, 1, 3 and 5 wt-%) alloys were prepared. The microstructure and mechanical properties were investigated and discussed. The experimental results show that the Mg–6Li–0.8Sn alloy is composed of three phases: α-Mg, Mg 2 Sn and Li 2 MgSn. With the addition of Al, the test alloys display typical α-Mg + β-Li duplex structures. The new Mg 17 Al 12 and LiMgAl 2 phases were found in the Mg–6Li–1Al–0.8Sn alloy. The lamellar-type AlLi phase was formed whereas the Mg 17 Al 12 phase disappeared in Mg–6Li–3Al–0.8Sn alloy. The LiMgAl 2 phase vanished in the Mg–6Li–5Al–0.8Sn alloy. The mechanical properties of as-extruded alloys were remarkably improved. The as-extruded Mg–6Li–3Al–0.8Sn alloy exhibited the best mechanical properties, with a yield strength, tensile strength and elongation of 209.8 MPa, 242.6 MPa and 15.5%, respectively.