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

摘要

Based on thermodynamic calculations, a die-cast Mg-1.6 wt. percent Ca-3.2 wt. percent Zn alloy was solution treated at 465 deg C and aged at 150, 175, 200 and 225 deg C for 1-96 h. In addition, cast samples were exposed to 200 and 225 deg 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.