Effect of melting modes on microstructure and tribological properties of selective laser melted AlSi10Mg alloy

This paper focuses on the effect of melting modes on microstructural evolution and tribological properties of AlSi10Mg alloy fabricated by selective laser melting (SLM). The results showed that the microstructures of SLM AlSi10Mg consisted of primary alpha-Al surrounded by cellular Si networks (similar to 500 nm) when fabricated in conduction mode, but has a finer cellular-like Si phase (similar to 200 nm) when fabricated in keyhole mode. The strong convection caused by the melt reflow and Marangoni convection under keyhole mode also resulted in deposition of nano-scale Si particles at the bottom of the molten pool. The SLM AlSi10Mg fabricated in keyhole mode exhibited better wear resistance than that fabricated in conduction mode. Compared to traditional as-cast specimens, both SLM specimens showed better wear resistance due to the unique cellular-like networks. The SLM technique offers a new approach for material processing that can be used to refine microstructures for improved tribological properties.