Effect of SiC ceramic nano-particles on microstructure and tribological performance of the AlTiVNbNi refractory high entropy alloy in a wide temperature range

A novel Al0.8TiVNbNi0.2(SiC)0.2 RHEA-based composite was fabricated by spark plasma sintering. The microstructure evolution and distinctions in high-temperature tribological properties of composite incorporating SiC nano-particles were systematically analyzed. The results demonstrate that SiC particles undergo in-situ reactions with the matrix alloy during the sintering process, resulting in the formation of TiC and Nb5Si3 phases, which significantly increases the microhardness of the composite. Simultaneously, wear resistance of Al0.8TiVNbNi0.2(SiC)0.2 composite is sharply ameliorated in a wide temperature range (RT to 800 °C). The non-exogenous matching interface between reinforced phases and matrix is the key to good tribological performance. For another, the generated Si oxides is contribute to continuity of the tribo-layer formed at high-temperatures, leading to a conspicuous reduction of wear rates.