In this study, the temperature gradient on lunar surface was simulated by deep cryogenic treatment and cryogenic thermocycling. The influence of these treatments on room and low temperature tensile properties and fracture behavior of the as-cast Mg–10Gd–3Y–0.5Zr alloy was then investigated. The results have shown that the cryogenic treatments caused the precipitation of Mg24(Gd, Y)5 phase and improved the ductility of the alloy. The deep cryogenic treatment almost has no influence on the tensile properties of the alloy, while the cryogenic thermocycling slightly improve its tensile properties at room temperature and slightly deteriorate the ultimate tensile strength of the alloy at low temperature. The cleavage fracture is the main fracture mechanism at both room and low temperatures. To conclude, this alloy can withstand the huge temperature gradient on the lunar surface and shows application perspective.
