Improving the applicability of wear-resistant Al–10Si–0.5 Mg alloy obtained through selective laser melting with T6 treatment in high-temperature, and high-wear environments

Abstract

This study investigated the effects of T6 treatments on the microstructural evolution process and mechanical properties of Al–10Si–0.5 Mg alloy specimens fabricated through selective laser melting (SLM). The applicability of the wear-resistant alloy for high-temperature applications was evaluated. The results reveal that the volume energy density (VED) of the laser used influences the structural morphologies of the SLM-fabricated alloy components. Ultrafine crystals and residual stress formed in the SLM-fabricated alloy specimen due to the rapid cooling rate, thus causing high hardness, high strength, and extremely low elongation values. T6 heat treatment decreases the hardness and tensile strength values of the alloy specimens but improves their elongation values because the residual stress is releases and the microstructure is changes such that a large number of Si particles are present in the Al matrix. The mechanical properties are influenced by the Si particle distribution due to tensile crack initiation at hard–brittle Si particles. The mechanical properties of the as-fabricated SLM alloy are comparable to those of 4384 alloys obtained after T6 heat treatment. The SLM-fabricated specimen that presents a high VED value after T6 heat treatment exhibits good wear resistance. The as-fabricated SLM alloy specimen retained its mechanical properties according to high-temperature tensile tests. The SLM-fabricated Al alloy is a potential candidate for wear-resistance and high-temperature applications.