The effect of quench-aging on the mechanical properties of Zn-27Al-1Cu alloy

The ternary alloy Zn-27Al-1Cu was produced by permanent mold casting. As-cast alloy was aged for different periods after being subjected to solution treatment followed by water quenching. The microstructure, mechanical properties and fatigue behavior of as-cast and heat-treated alloy were then investigated. The quench-aging eliminated the as-cast dendritic structure and produced a uniform microstructure consisting of large grains combined with precipitates. The hardness and tensile strength generally increased, whereas the ductility slightly decreased with aging time. Under all conditions, the longest fatigue life was obtained from the alloy that had been aged for 0.5 h, while the alloy which had been aged for 10 h exhibited the shortest. The fatigue properties were found to be more dependent on impact toughness and elongation, rather than tensile strength.