Enhancing the mechanical properties and corrosion resistance of CrCoNi medium entropy alloy by melt superheating treatment

The microstructural evolution and its effects on the mechanical properties, friction performance, and corrosion resistance of CrCoNi medium entropy alloy (MEA) under different superheating conditions are investigated. Through hardness testing, compression testing, friction and wear experiments, and electrochemical analysis, the influences of superheating temperature on CrCoNi MEA performance are systematically examined. Results show that the hardness of CrCoNi MEA increased by 19.7 % when the superheating temperature rising to T 4 . With the superheating temperature increasing, the strength of the plastic deformation stage increases significantly, which is mainly due to the grain refinement hinder the dislocation movement. Superheating treatment effectively reduces the wear loss and improves wear resistance. And reduces the abrasive wear and adhesive wear of the friction surface. The corrosion current density decreases to 1.493 μA/cm 2 with the superheating temperature at T 4 , which indicates that the corrosion resistance of the CrCoNi MEA can be effectively improved by superheating treatment. Nyquist and Bode plots show an increase in the passivated film density and enhanced protective performance on the superheated surface. In summary, superheating treatment significantly enhanced the mechanical properties and corrosion resistance of CrCoNi MEA by regulating microstructure, providing a theoretical basis for its engineering application. • The superheated samples are prepared using vacuum arc melting at different power. • The effects of superheating temperature on CrCoNi MEA performance are examined. • The hardness and elastic limit increase by 19.7 % and 31.2 %, respectively. • The friction coefficient and wear loss reduce by 11.6 % and 8.8 %, respectively. • The melt superheating treatment improves the CrCoNi MEA corrosion resistance.