Research on microstructure and mechanical properties of multi-particles synergistically reinforced aluminum matrix composites by laser additive manufacturing

With the increasing demand for lightweight, high-strength, and durable structural components in aerospace and automotive industries, particle-reinforced aluminum matrix composites (AMMCs) have attracted extensive attention due to their low density, high specific strength, and excellent wear resistance. In this study, aluminum composites with 0.5 wt% TiN +0.5 wt% Si₃N₄ and 1 wt% TiN +1 wt% Si₃N₄ reinforcements were fabricated using selective laser melting (SLM) to achieve improved performance, leveraging the strengthening effects of different reinforced particles. During the high-temperature SLM process, TiN particles melted and released Ti atoms, which facilitated the formation of Al₃(Ti, Sc, Zr) phase. Compared to the as-deposited aluminum alloy, the composites exhibited enhanced tensile strength of 415.42 MPa (0.5 wt% TiN + 0.5 wt% Si₃N₄) and 446.63 MPa (1 wt% TiN + 1 wt% Si₃N₄). The enhanced strength is primarily attributed to grain refinement and precipitation hardening induced by the reinforced particles.