Microstructure and mechanical properties of CoCrFeNiMo high-entropy alloy coatings

The CoCrFeNiMo coatings were prepared by laser cladding on 45 steel surface. The microstructure, hardness and wear resistance of CoCrFeNiMo high-entropy alloy were investigated by means of scanning electron microscopy, X-ray diffractometer, hardness tester and wear tester. The effect of laser scanning speed on the microstructure and mechanical properties of the coating was studied. Experimental results show that the coating and matrix combines well, the microstructure of the coatings is mainly composed of equiaxed grains. The phase structure of the coating is mainly composed of face-centered cubic (FCC) structure, body-centered cubic (BCC) structure and Laves phase. There is a slight segregation of Mo element. The CoCrFeNiMo coating has high hardness, the highest surface hardness is 741 HV. Fine-grained strengthening, BCC structure and Laves phase provided a guarantee for the excellent wear resistance of the coating. With the increase of scanning speed, the structure is refined, the hardness is improved and the wear resistance is enhanced.