Oxidation behaviour of Mg-2.1Gd-1.1Y-0.82Zn-0.11Zr alloy at high temperatures

The oxidation behaviour of Mg-2.1Gd-1.1Y-0.82Zn alloy at high temperatures was studied by thermogravimetric analysis. Results showed that the weight gain of samples mainly occurred in the temperature-rise stage. This result was ascribed to the absence of protective scales and the rapid transport of oxygen inward through the macro-defects of discontinuous oxide scales. After the formation of protective (Gdx, Y2−x)O3 film, dense scales retarded the inward diffusion of oxygen ions (O2−) and improved the oxidation resistance of the alloy at high temperatures. Moreover, when alloy coupons were set in a box furnace at 1003 K, the molten alloy did not burn until 120 min, indicating high safety.