Microstructure and mechanical performance of new Al0.5CrFe1.5MnNi0.5 high-entropy alloys improved by plasma nitriding

Effects of plasma nitriding at 525 °C on microstructure and mechanical performance of a brand-new Al0.5CrFe1.5MnNi0.5 high-entropy alloy (HEA) were investigated. This alloy exhibits a large age hardening effect at temperatures from 600 to 800 °C and can be well-nitrided in the as-cast condition or the homogenized and furnace-cooled state. The nitrided layer has a thickness around 75 μm and a peak hardness level of Hv 1250 near the surface. The nitrided Al0.5CrFe1.5MnNi0.5 alloys exhibit superior adhesive wear resistance to conventional nitrided steels by 25–54 times due to their much thicker highly-hardened layer and higher peak hardness than that of conventional steels.