Investigations on the microstructure, mechanical, corrosion and wear properties of Mg–9Al–xGd (0, 0.5, 1, and 2 wt%) alloys

Magnesium alloys with the lowest structural density exhibit unique applications in the automotive and aerospace fields. Rare earth addition is a promising method to enhance the mechanical properties of the Mg alloys. In the present study, the magnesium-aluminium (Mg-9Al) alloy containing varying wt% of gadolinium (Gd) is synthesized using the casting technique. The microstructure, mechanical, corrosion, and wear properties of the developed Mg-9Al-xGd alloy are evaluated and compared to the base Mg-9Al alloy. Microstructural investigation shows significant grain refinement and the presence of Al2Gd in addition to β-Mg17Al12in the Gd-added alloys. Under tensile loads, the developed Mg-9Al-2Gd alloy exhibits enhancements in ultimate and yield strengths. The corrosion resistance of the alloys is found to increase with increasing Gd content and is optimal at 2 wt%. Considering the higher hardness and dispersity of the Al2Gd phase, Mg-9Al-2Gd has exhibited a higher wear resistance than that of the as-cast Mg-9Al alloy.