Microstructures and mechanical properties of as-cast Mg–5Al–0.4Mn–xNd (x = 0, 1, 2 and 4) alloys

Mg–5Al–0.4Mn–xNd (x = 0, 1, 2 and 4 wt.%) alloys were prepared by metal mould casting method. The microstructures and mechanical properties were investigated. The results demonstrated that Al11Nd3 phase was formed and mainly aggregated along the grain boundaries with the addition of Nd. Meanwhile, the grain sizes were greatly reduced with the increasing Nd content. The tensile properties of the as-cast alloys were also improved at room temperature and 423 K, and the alloy containing 2 wt.% Nd exhibited the highest tensile strength. The improvement of the tensile strength was mainly attributed to the refined grains and the highly thermal stability of Al11Nd3 precipitate that effectively prohibited the dislocation movement and grain boundary sliding.