Creep Properties of Mg-Gd-Y-Zr Alloys

High temperature creep properties of Mg–Gd–Y–Zr alloys have been evaluated quantitatively. Creep test was carried out under a stress range of 50–100 MPa and a temperature range of 250–300°C. Within the limits of the creep test conditions used in this study, the activation energy for creep of investigated alloys is in the range of 160–240 kJ/mol, and the stress exponent is in the range of 3.7–5.2. Accordingly, the creep mechanism of the investigated alloys is considered to be power law creep. Creep resistance of the investigated alloys depends on chemical composition, it improves with increase in gadolinium content, which implies an increase in the quantity of precipitates. The creep resistance of the high gadolinium-containing alloys exceeds that of the existing heat resistant magnesium alloy, WE54A alloy.