Microstructure and Properties of 316L Lattice/Al Composites Fabricated by Infiltration with Different Aspect Ratios of Lattice

The interfacial behavior between lattice reinforcement and aluminum matrix plays an important role in determining the mechanical and tribological properties of lattice-reinforced aluminum matrix composites. In this study, 316L lattices with different aspect ratios were prepared by laser powder bed elting (LPBF) technology, and LY12 aluminum alloy was infiltrated under vacuum conditions. The effects of lattice aspect ratio on the interfacial reaction, microstructure, hardness, compressive strength, and wear resistance of the composites were systematically studied. First-principles calculations show that FeAl2 and FeAl3 intermetallic compounds are preferentially formed at the interface, showing good thermodynamic stability and mechanical properties. The microstructure analysis shows that the increase in aspect ratio promotes the formation of coarse FeAl3 phase and network AlCu, while a too-large aspect ratio leads to the instability of microstructure and the generation of microcracks. When the lattice constant is 10 mm and the diameter of the support is 1 mm (BCC-10-1), the composite material has the best wear resistance, and the specific wear rate is 3.07 × 10−4 mm3/(N·m). These findings provide valuable insights into the design of high-performance lattice-reinforced aluminum matrix composites with customized interface properties.