Microstructure and Wear Resistance of a Ni–Fe–Si–B Amorphous Composite Coating by Laser Cladding

In this study, a Ni–Fe–Si–B amorphous composite coating is coated on H13 steel by laser cladding. Coatings are systematically investigated for their microstructure, phase composition, tribological behavior, and mechanical characteristics. X-ray diffraction results demonstrate that the cladding layer can be divided into the interface, transition, and compositionally stable zones, where the coating has both crystalline and amorphous phases, with up to 57% of the coating being amorphous. According to scanning electron microscopy and transmission electron microscopy analyses, the middle and surface regions of the coating mainly consist of (Fe_0.5Ni_0.5)₃Si, Fe₂B, Fe₂NiB, Ni₃₁Si₁₂, and amorphous phases. The in-situ generated Fe₂B phase is uniformly distributed within the coating, leading to a significant enhancement in microhardness. The greatest hardness of the coating is approximately 927.04 HV_0.2. The composite coating exhibits excellent wear resistance, which is approximately 1.71 times greater than that of the substrate. Minor abrasive wear constitutes the primary wear mechanism for the coatings.