Microstructural stability of heat-resistant high-pressure die-cast Mg-4Al-4Ce alloy

The thermal stability of Al-RE (rare earth) intermetallic phases with individual RE for heat-resistant high-pressure die-casting Mg-Al-RE alloys is investigated. The results of this study show that the main strengthening phase of Mg-4Al-4Ce alloy is Al11Ce3, whose content is about 5 wt.% according to quantitative X-ray diffraction phase analysis. The Al11Ce3 phase appears to have high thermal stability at 200 degrees C and 300 degrees C, while phase morphology change with no phase structure transition could occur for Al11Ce3 when the temperature reaches 400 degrees C. Furthermore, besides the kinds of rare earths and temperature, stress is also an influencing factor in the microstructural stability of Mg-4Al-4Ce alloy.