Tribological Performance of a Tizrnbmo0.6 Refractory High Entropy Alloy at Elevated Temperatures

Refractory high-entropy alloy (RHEA) has attracted much attention in the high-temperature field for the sake of excellent high-temperature resistance, mechanical properties, and wear performance. One kind of RHEAs, e.g., Ti-Zr-Nb-Mo, is a potential candidate for wear resistance materials due to its high strength and low modulus. In this paper, the microstructure, oxidation resistance and tribological properties of TiZrNbMo 0.6 RHEA were studied. SEM and EDS were used to characterize the morphology and compositions of the wear surfaces and cross-sections, as well as the Si 3 N 4 counterparts. The results indicate that the TiZrNbMo 0.6 alloy has the most excellent wear resistance due to forming a compacted and continuous glaze layer on the surface at the temperature of 500 °C. The evolution of the wear mechanism at various temperatures has been discovered and the oxidation test has been conducted to explain the mechanisms of tribological properties at high temperatures. The dominant wear mechanism changes from abrasive wear and adhesive wear at room temperature to oxidative wear and slight abrasive wear at 500 °C. With the wear temperature increasing to 800 °C, the dominant wear mechanism is severe oxidative wear, following by partly abrasive wear. This results in a higher wear rate at 800 °C than that at 500 °C