SiC is well-known as an effective carbon inoculation material for grain refinement of Mg-Al-based alloys. In this study, grain refinement ability of stir-casted Al-SiC composite for Mg-Al-based alloy was investigated to confirm the feasibility of industrial application. Commercialized Al-20 vol.-% SiC composite ingot was used in AZ91 alloy as a grain refiner, and grain size of AZ91 alloy dramatically reduce from 650 to 74 µm and become uniform with 0.7 wt-% Al-SiC composite addition. And acicular type Al-Mn phase existed at the grain boundaries are changed to polygonal type and positioned inside grains after grain refinement. These morphological changes of small grain size and uniform second phases contributed to the excellent mechanical properties of AZ91 alloy.

This study evaluates the corrosion behavior of high-pressure die-casting AZXW alloys, focusing on the influence of Al content (6, 9, 11, and 13 wt.%). The Al effect on corrosion resistance is characterized by a dual effect. The corrosion rates initially increase as Al content reaches 9 wt.%, which is attributed to a higher fraction of isolated β phases acting as micro-galvanic cathodes. Conversely, further increasing the Al content to 13 wt.% promotes the development of continuous network β phases, which serve as an efficient physical barrier that stops corrosion propagation. Furthermore, the Volta potential difference (VPD) between the α-Mg and β-phase decreases with rising Al concentrations, alleviating galvanic corrosion, further lowering the corrosion rate.