Effects of laser energy density on microstructure, texture and tribological property of CoCrFeMnNi high entropy alloy coatings fabricated by laser cladding

Abstract

Single-phase CoCrFeMnNi high entropy alloy (HEA) coatings were prepared using laser cladding methods, with different energy densities achieved by adjusting the laser power to 3200 W, 3500 W, and 3800 W. Microstructural analysis revealed that all coatings can be categorized into three distinct regions, where the temperature gradient, direction of heat flow and the preferred orientations of grains determined the grain morphology. Mechanical tests demonstrated that the coating exhibited the lowest hardness (160 ∼ 200 HV) and the best wear resistance when the laser power was set to 3500 W, attributed to the intrinsic properties of CoCrFeMnNi and the presence of oxidative wear. The predominant wear mechanism of LP3500 shifted from abrasive wear to adhesive wear as the loads increased from 15 to 45 N.