Microstructure and wear behavior of AlxCo1.5CrFeNi1.5Tiy high-entropy alloys

A series of AlxCo1.5CrFeNi1.5Tiy high-entropy alloys with different Al and Ti contents were designed, and their phase and microstructure were investigated. The adhesive wear behavior and mechanism were also studied and compared with the conventional wear-resistant steels SUJ2 and SKH51. The amounts of Al and Ti strongly affect the phase and microstructure, particularly the amount and morphology of the hard η-(Ni, Co)3Ti phase. It was found that the wear resistance of the Co1.5CrFeNi1.5Ti and Al0.2Co1.5CrFeNi1.5Ti alloys is at least two times better than that of conventional wear-resistant steels with similar hardness. The excellent anti-oxidation property and resistance to thermal softening in these high-entropy alloys are proposed to be the main reasons for the outstanding wear resistance.