Design materials based on simulation results of silicon induced segregation at AlSi10Mg interface fabricated by selective laser melting

Abstract

AlSi10Mg fabricated by selective laser melting (SLM) had a unique network-like silicon-rich structure, and the mechanism for its formation was explained by molecular dynamics (MD) simulations. The effects of the silicon-rich phase and Mg-containing structure on corrosion were studied by first-principles methods. According to the simulations, corrosion resistant materials were designed, samples with laser powers of 150 W, 200 W and 250 W were fabricated. The results indicated that a local thermal gradient during laser printing caused Si segregation, and the rapid cooling rate lead to a large number of subgrains, which assisted precipitation. The difference in potential caused galvanic corrosion, and a structure with low work function in the molten pool caused pitting. The corrosion resistance of materials processed with a high laser power increased.