The tribological properties of Al^sub 0.6^CoCrFeNi high-entropy alloy with the σ phase precipitation at elevated temperature

The microstructure, hot hardness and oxidation behavior of Al0.6CoCrFeNi high-entropy alloy were investigated. Moreover, the effect of the temperature on the tribological properties of Al0.6CoCrFeNi high-entropy alloy was studied. The results showed that the σ-CrFe phase was precipitated after heat treatment. The hardness of HEAs increased from 278 to 480 HV. The HEAs possessed higher wear resistance than that of the conventional alloys at elevated temperatures. The wear resistance of annealed alloy was nearly 3 times higher than that of GCr15 steel at 600 °C. With increasing temperature, the predominant wear mechanism was transformed from the abrasive wear to the mild oxidative wear as well as delamination wear with increasing the temperature.