Microstructure evolution and mechanical properties of Al-Cu alloys inoculated by FeBSi metallic glass

A significant refining effect of α-Al grains from 200μm to 42μm can be achieved by addition of 0.1wt.% FeBSi metallic glass, which is mainly attributed to the crystallization of Fe₂B phase being able to act as the heterogeneous nucleation sites of α-Al grains during solidification. Within an inoculation time of 30min, the inoculated Al-Cu alloys remain a fine grained structure. Moreover, the strength and ductility of the inoculated alloys are simultaneously improved. The enhanced properties of Al-Cu alloy inoculated by metallic glass are mainly due to the refined α-Al grains, the small θ' precipitates distributed homogeneously in grain interior and the formation of the nano-sized AlCuFeMn phase. This study provides a high-efficiency and cost-effective processing technique of refinement in this alloy, and at the same time, broadens the industry application of metallic glass.