Abstract:The microstructure and mechanical properties of ZK60 Mg alloy were investigated under different solution treatments and artificial aging conditions. When as-cast ZK60 alloy was solution treated at 400 °C for 10 h and artificially aged at 150 °C, the volume fraction of precipitates increased with the aging time up to 30 h. When the as-cast ZK60 alloy was solution treated at 400 °C for 10 h and artificially aged at 200 °C for 15−20 h, the volume fraction of precipitates reached a peak value. Tensile test at room temperature showed that a high density of the second phase precipitates was beneficial to improving the strength and elongation. Solution treatment at 400 °C for 10 h and artificial aging at 150 °C for 30 h is considered the optimum heat treatment condition to obtain a good combination of strength and ductility.

Key words: Mg alloy; heat treatment; precipitate; strength; ductility