Comparison of Microstructure and Properties of CoCrMo Coatings Prepared by High-Speed and Conventional Laser Cladding

High-speed laser cladding technology is an innovative process that reduces costs and enhances coating quality. In this study, CoCrMo wear-resistant coatings were fabricated on a 40Cr steel substrate using high-speed laser cladding technology and compared to CoCrMo coatings produced by traditional methods. The effects of both processes on the microstructure, nanoindentation characteristics, and wear behavior of CoCrMo coatings were examined. The results show that the phase compositions of both coatings include γ-Co solid solution and ε-Co solid solution. The high cooling rate of high-speed laser cladding significantly suppressed Mo precipitation, enhancing Mo solid solution strengthening. Additionally, the fine-grain strengthening effect induced by the high cooling rate contributed significantly to the coatings’ mechanical properties. The nano-hardness of the HS-CoCrMo coatings reached approximately 5.18 ± 0.23 GPa, 1.2 times higher than that of the N-CoCrMo coatings. Furthermore, the generalized hardness, H/E ratio, and H3/E2 ratio of HS-CoCrMo coatings were improved. This increase in nano-hardness significantly boosted the wear resistance of HS-CoCrMo coatings, yielding an average friction coefficient of approximately 0.466, with wear volume and specific wear rate values of 6.55 × 106 μm3 and 0.87 × 10−5 mm3/N·m, respectively, outperforming the N-CoCrMo coatings. The main wear mechanisms for the HS-CoCrMo coatings were abrasive wear, adhesive wear, and oxidative wear. In conclusion, high-speed laser cladding technology produces high-performance, wear-resistant coatings with high productivity, offering broader application prospects for the metallurgical and power industries, while effectively reducing production cycles and usage costs.