Microstructure and properties of 316 L lattice/Al composites by additive manufacturing and infiltration with different temperature

Abstract

Interface between lattice reinforcement and matrix played a key factor on properties of the lattice reinforced aluminum matrix composites. However, the effect of interface composed of intermetallic compounds on the properties of 316L lattice/Al composites was still unclear. In this study, 316L lattice reinforced aluminum composite with continuous interface were prepared by combining laser powder bed fusion (LPBF) and vacuum infiltration, and effect of infiltration temperature on interface evolution and properties of the composite was investigated. Results indicated that a continuous dual-phase interfacial layer consisting of hard intermetallic compounds η-Fe2Al5 and θ-FeAl3 was formed between the reinforcement and matrix due to diffusion and reaction of iron and aluminum atoms, and the size of needle-type FeAl3 phase in the interfacial zone increased when infiltration temperature was up from 800 °C to 900 °C. It also confirmed that reinforced by 316L lattice and hard intermetallic compounds layer, the composite showed excellent mechanical and wear resistant properties, with compressive strength of 657 ± 32MPa and specific wear rate of 0.20 × 10−3 (mm3/N·m) for the sample prepared at 800 °C, which were over 10 times and one fifth of that of the aluminum matrix individually. This study provides a new strategy for developing 316L lattice/Al composites with excellent properties.