Effect of Ti and Nb on the Microstructure and Wear Resistance of CoCrFeNiTixNby High‐Entropy Alloy Coatings Prepared by Laser Cladding

High‐entropy alloys (HEAs) represent a novel class of materials exhibiting enhanced wear resistance, characterized by multicomponent structures comprising equal or near‐equal ratios of constituent elements. To strengthen the surface wear resistance and hardness of Q235, CoCrFeNiTi x , and CoCrFeNiTi 0.8 Nb y ( x , y : molar ratio, x = 0.8, 1.0; y = 0.25, 0.75), HEA coatings are prepared via laser cladding. Furthermore, the study demonstrates the efficacy of a laser cladding technique for the preparation of HEA coatings. The microstructure, microhardness, and wear resistance of the HEA coatings are studied. The phase of the CoCrFeNiTi x Nb y HEA coatings with Nb addition changes from body‐centered cubic (BCC), face‐centered cubic (FCC) to BCC, FCC, and Laves phases. Transmission electron microscope has revealed that the Ti exists in a FCC structure in HEAs. The hardness of the CoCrFeNiTi x Nb y HEA coatings is enhanced, where the hardness of the CoCrFeNiTi 0.8 Nb 0.75 alloy (710HV), which is the highest among CoCrFeNiTi x Nb y HEA coatings, is four times that of the substrate. The increase of the microhardness is mainly due to the fine‐grain strengthening, solid solution strengthening, and dispersion strengthening. And the CoCrFeNiTi 0.8 Nb 0.75 coating shows good wear resistance; the wear rate is 0.135 × 10 −6 mm 3 N −1 m −1 .