Effect of WC content on the microstructure and wear resistance of laser cladding AlCoCrFeNiTi0.5 high-entropy alloy coatings

Abstract

AlCoCrFeNiTi0.5+x(WC) high-entropy alloy (HEA) coatings with varying WC content (x = 0, 10, 20, and 30 wt%) were prepared by laser cladding. The results of the microstructure analysis showed that the AlCoCrFeNiTi0.5 coating consisted of body-centered cubic (BCC1) and BCC2 phases, while additional TiC and W2C phases formed within the coating with the WC content reaching 20 wt% mol. The addition of WC particles acted as a barrier to grain growth, preventing grains from growing larger. Additionally, the in-situ TiC phase was distributed at the grain boundaries and further inhibited the grains growth. The grain refinement and increase in dislocation density jointly improved the ability of the coating to resist plastic deformation. Due to the addition of the WC particles, the micro-hardness and wear resistance of the coatings improved considerably. The AlCoCrFeNiTi0.5 coating with 30 wt% WC exhibited the best performance. Its hardness increased by 35.8 % and wear rate decreased by 58.2 % compared with the AlCoCrFeNiTi0.5 coating.