Microstructure and Wear Resistance of Laser Clad CoCrFeNiTiNbBx High Entropy Alloy Coatings.

CoCrFeNiTiNbBx high entropy alloy coatings were prepared on AISI H13 steel using laser cladding. The effect of the boron content on the microstructure and wear resistance of the coatings was systematically investigated. Results showed that a TiB phase was formed in situ after adding boron, which promoted the formation of short rod-like dendrites and equiaxed crystals in the coatings underlying brittle fractures of massive coarse dendrites. The formation of macrocracks was not observed in the coatings after adding boron. The microstructure was more fine and uniform as the boron content increased. The microhardness and wear resistance of the coatings were gradually increased with the increase in the boron content. The microhardness and mass loss of the coatings were 1.25 and 0.61 times that of the coatings without boron, respectively, for a boron content of 1.25. The wear mechanism of the coatings was the adhesive wear and abrasive wear when the boron content was less than 1.0, and the abrasive wear when the boron content was not less than 1.0. [ABSTRACT FROM AUTHOR]