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This study investigated the microstructure, mechanical properties, impact toughness, and erosion characteristics of Al-10Si-Mg alloy specimens manufactured using the selective laser melting (SLM) method with or without subsequent T6 heat treatment. Furthermore, the erosion phase transformation behavior of the test specimens was analyzed, and the effect of the degradation mechanism on the tensile mechanical properties and impact toughness of the SLM Al-10Si-Mg alloy specimens before and after particle erosion was compared. The experimental results indicated that the Al-10Si-Mg alloy subjected to T6 heat treatment has better erosion resistance than the as-fabricated material. The tensile strength and fracture toughness of both specimen groups decreased due to the formation of microcracks on the surface caused by particle erosion. Nevertheless, the erosion-induced silicon nanoparticle solid solution softens the Al matrix and improves the elongation of the SLM Al-10Si-Mg alloy.

Al-Si alloys exhibit promising wear resistance, thus being mainly employed to weld Al alloy parts and processed into components of equipment. During the new continuous casting direct rolling (CCDR) process, the raw material gradually cools and solidifies, simultaneously plastically deformed. Hence, the materials manufactured through the CCDR process presented an unparalleled microstructure. The experimental results indicated that the strength of the CCDR Al-Si alloy can be increased through cold rolling. A two-stage heat treatment (solid solution and aging treatment) was introduced to improve the ductility and satisfy the industrial application. Furthermore, the erosion wear characteristics and fracture mechanism of the CCDR Al-Si alloy dominated by the ductility were confirmed. Both cold rolling specimens (FR) and those with heat treatment (FRH) showed greater wear resistance than as-manufactured (F). The FR specimens exhibited greater wear resistance owing to a higher Al matrix strength at a lower impact angle; on the other hand, at a higher impact angle, the FRH specimens with a softer Al matrix presented better wear resistance due to the formation of a lip structure to reduce material removal. The TEM results confirmed that the nanoscale grains formation was induced in the erosion-affected region and affected the Si concentration. Conclusively, the heat-treated CCDR Al-Si alloy possessed excellent erosion resistance and workability, which can serve as a reference processed as wear-resistant mechanical parts.

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