Tribological properties and wear mechanisms of TixVNbTaWy RHEAs sliding against Si3N4 ceramic balls: The effects of Ti and W contents

Abstract

Three new TixVNbTaWy RHEAs with different contents of Ti and W were prepared by mechanical mixing and spark plasma sintering. The effects of Ti and W contents on the mechanical and tribological properties were explored, with a focus on the wear mechanisms of the alloys sliding against Si3N4 ceramics from room temperature to 900 °C. The results showed that all three alloys exhibited high compressive strength and plastic strain of > 12% at room temperature. More crucially, the wear rate of the optimized alloy can be as low as 6.8 × 10−6 mm3/(N·m) at 600 °C. Friction-induced subsurface strengthening and the formation of continuous oxide films and plastic deformation layers played an important role in reducing the wear rate.