Enhancing the Properties of As-Cast Al6061 Composites with Ti3C2Tx Reinforcement: Grain Refinement, Strength Improvement, and Self-Lubricating Wear Behavior

Ti3C2Tx/Al6061 composites were fabricated via vacuum induction melting, with systematic analysis conducted on their microstructure, mechanical properties, and wear behavior. Findings indicate that Ti3C2Tx addition significantly refined the composite grain size. Uniformly dispersed Ti3C2Tx particles promoted heterogeneous nucleation, reducing the average grain size by 44.7% compared to the matrix at the optimal 2 wt.% addition. Strong interfacial bonding ensured efficient load transfer, resulting in a 48.4% increase in tensile strength for the 2 wt.% Ti3C2Tx/Al6061 composites compared to the matrix alloy, while elongation decreased by 11.7%. Tribological analysis revealed that the wear rate of 2 wt.% Ti3C2Tx/Al6061 composites increases with applied load but remained substantially lower than Al6061 under all tested conditions. This excellent wear resistance is attributed to the synergistic effect of the protective mechanically mixed-layers formation and the inherent self-lubrication property of Ti3C2Tx during sliding contact. With increasing load, the friction coefficient and tendency for microcracking on the worn surface of the composite increased, and the dominant wear mechanisms transitioned from abrasive and adhesive wear to delamination wear.