Effect of TiC particles on microstructure and wear performance of Al-5Mg alloy fabricated by wire arc additive manufacturing

Al-Mg alloys fabricated via Wire Arc Additive Manufacturing (WAAM) exhibit notable advantages in production efficiency and weight reduction, making them particularly suitable for weight-sensitive fields like aerospace and automotive industries where large-scale and complex components are required. However, their inherent directional grain growth and insufficient hardness lead to insufficient wear resistance. This research examines the influence of interlayer TiC particle incorporation (0.2–0.8 wt%) on the microstructural evolution and tribological behavior of wire arc additively manufactured Al-5Mg alloys. Results demonstrate that TiC particles significantly refine grain size and reduce anisotropy of Al-5Mg alloys. With 0.6 wt% TiC addition, the average grain size decreases from 74.5 μm to 26.2 μm, accompanied by synergistic improvements in hardness (81.2 HV to 116.6 HV) and tribological properties. The coefficient of friction (COF) and wear rate exhibit a marked decline across varying applied loads. This enhancement is primarily originated from TiC's inherent hardness and strong interfacial bonding with the Al matrix, enabling effective load transfer during friction. However, TiC pseudo-dispersion degrades the wear performance when TiC content exceeds 0.6 wt%. The findings confirm that optimized TiC addition effectively enhances the tribological properties of WAAM Al-5Mg alloys.