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 1–96 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 Ca 2Mg 6Zn 3.