Mechanical and Tribological Properties of Fe- and Ni-based Coating Material under Laser Cladding Process

Fe- and Ni-based coatings have been prepared on the surface of an 18CrNiMo7-6 alloy substrate using laser cladding technology. The microstructure, wear resistance, and mechanical properties of the coatings and substrate were systematically investigated. The results indicate that the wear resistance of Ni-based coatings is inferior to that of Fe-based coatings. The friction coefficients of the coatings and substrate range between 0.6 and 0.7. Moreover, the Ni content significantly influences the mechanical and tribological properties. Increased Ni content promotes the precipitation of the γ phase in both Fe- and Ni-based coatings. Higher Ni content degrades the microhardness and wear resistance of Fe-based coatings while enhancing these properties in Ni-based coatings. Additionally, Ni-based coatings produced from powders containing 80% Ni exhibit superior comprehensive properties, with a Young’s modulus exceeding 210 GPa and a microhardness ranging from 200 to 300 HV, comparable to that of the substrate. Although the tensile strength of these coatings is half that of the substrate, the total elongation is double. Fracture mechanisms reveal brittle-ductile fractures in the substrate and ductile fractures in the coatings.