An as-extruded Mg-10Li-3Al-1Zn-0.3Mn alloy was treated by solution and aging at different temperatures.The microstructure and mechanical properties of the alloy were analyzed by OM

XRD and hardness testing.The results show that the as-extruded alloy is composed ofα-Mg

β-Li and MgLiAl

2

phase.α-Mg phase is distributed in the alloy in blocks of different sizes with low hardness（46.8 HV）.The hardness of the alloy is increased gradually with the increase of solution temperature.α-Mg phase is dissolved into the matrix alloy with solid solution at different temperatures for 30 min

and the hardness of the alloy is increased with increasing of solution temperature which result in the increase ofα-Mg phase solution.The hardness of the alloy reaches up to 110 HV after solution at 460℃ for 30 min

which is 135% higher than that of extruded alloy.The hardness of the alloy is decreased with the increase of solution time at 460℃ for 30

60 and 90 min.After artificial aging and natural aging

the hardness of the alloy is decreased.After aging at 70℃ for 1 hour or artificial aging for 20 days

the hardness of the alloy is finally stabilized at about 75 HV

which is about 60%higher than that of the extruded alloy.