Microstructure and creep resistance of Mg–10Zn–4Al–0.15Ca permanent moulding alloy

Abstract

In this paper, the microstructure of Mg–10Zn–4Al–0.15Ca (wt-%) (ZAC104015) magnesium alloy was characterised in the as cast condition. Thermal analysis was performed to determine the liquidus, solidus, and intermediate reactions that occur upon cooling. The results show that this alloy is composed of α-Mg and two intermetallic phases containing calcium τ'₁ and τ'₂. These two intermetallic phases have the same type of crystal structure as that of phase τ (Mg₃₂(Al,Zn)₄₉). The thermal stability of the phases τ, τ'₁, and τ'₂, were also evaluated. This experimental study indicates that the phase τ'₂ is more stable than τ and τ'₁ at elevated temperature and directly related to creep resistance improvement.