Solidification, solution treatment and age hardening of a Mg-1.6 wt.% Ca-3.2 wt.% Zn alloy

Based on thermodynamic calculations, a die-cast Mg-1.6 wt.% Ca-3.2 wt.% Zn alloy was solution treated at 465 °C and aged at 150, 175, 200 and 225 °C for 196 h. In addition, cast samples were exposed to 200 and 225 °C for up to 32 days. The microstructures of the as-cast, solution-treated and aged alloys are in good agreement with the thermodynamic calculations. A typical age hardening and softening response was obtained during the aging treatment, as well as during the exposure to elevated temperatures. The alloy hardening correlates to the precipitation of Ca2Mg6Zn3.