Microstructure and wear mechanism of CoCrCuFeNiVx high entropy alloy by sintering and electron beam remelting

In this study, electron beam current was used to modify the surface of CoCrCuFeNiVx (x = 0, 0.6, 1.0) prepared by sintering to improve wear resistance. Thermal behavior, microstructure, hardness and wear resistance of the alloy were investigated with conclusions below. CoCrCuFeNiV alloy is composed of three phases (FCC, Cu-rich phase, V-rich phase) after sintering and electron beam remelting. V is beneficial to reduce the enthalpy of CoCrCuFeNiVx and promote the stabilization of FCC solid solution phase. The hardness of CoCrCuFeNiV can reach up to 408.4HV, which is 35.4% higher than CoCrCuFeNi (301.5HV). Moreover, the wear resistance is greatly improved by V due to the formation of alloy hardening layer and oxide film on the surface, and the wear rate is reduced by 80.6%. The wear mechanism of CoCrCuFeNiV is mainly abrasive wear, supplemented by adhesive wear and oxidative wear. •CoCrCuFeNiV alloy powder consists of three phases (FCC, BCC, V concentrating phase) after 15 h ball milling, while it is composed of FCC and V concentrating phase after sintering and electron beam remelting.•V is beneficial to reduce the enthalpy of CoCrCuFeNiVx and promote the stabilization of FCC solid solution phase. .•The hardness of CoCrCuFeNiV with electron beam remelting treatment can reach up to 408.4HV, which is 35.4% higher than CoCrCuFeNi (301.5HV).•The wear resistance of CoCrCuFeNi is greatly improved by V element, and the wear rate is reduced by 80.6%.•CoCrCuFeNiV is mainly abrasive wear, supplemented by adhesive wear and oxidative wear. The wear resistance is significantly improved by forming alloy hardening layer and oxidation film on the surface.