Synthesis of a high-entropy (TiVCrMo)₃AlC₂ MAX and its tribological properties in a wide temperature range

A novel high-entropy (TiVCrMo)₃AlC₂ MAX with a solid solution of Ti, V, Cr, and Mo atoms in its lattice is synthesized. The tribological properties as well as the wear mechanism of the high-entropy MAX against a Si₃N₄ counterpart in a wide temperature range from room temperature to 800 ºC in the air are systematically studied. Combined with the experimental observations and the theoretical simulations, the effects of high-entropy structure on the tribological behaviors of the (TiVCrMo)₃AlC₂ MAX are illuminated. Benefited from the high-entropy structure, the (TiVCrMo)₃AlC₂ MAX presents an improved hardness and oxidation resistance, which contributes to a dry-sliding tribological behavior in the temperature window of R.T.–600 °C. While further increasing the operating temperature to 800 °C, hydrodynamic lubrication emerges, which boosts the lubricity in the high-entropy (TiVCrMo)₃AlC₂ MAX.