Effect of Nano-La₂O₃ and Mo on Wear Resistance of Ni60a/SiC Coatings by Laser Cladding

To improve the wear resistance of the TMR blade and investigate the effect of nano-La₂O₃ and Mo on the wear resistance of laser cladding coating. 65Mn blade as the substrate, La₂O₃, Mo and Mo-La₂O₃ composite powders were added into Ni60a/SiC composite powder. Using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and the CFT-I surface synthesizer, the phase composition, element distribution and friction and wear properties of the coating were analyzed to obtain the best composition of the composite coating. The results showed that the wear resistance of Mo-La₂O₃-Ni60a/SiC composite coating was the best. The coating was analyzed by X-ray diffraction and X-ray photoelectron spectroscopy. The coating contained hard phases such as CrB, CrC and Cr₇C₃, and the element distribution was uniform. It can be seen from the scanning electron microscope that the addition of nano-Mo and La₂O₃ improves the toughness and compactness of Ni60a/SiC composite coating, and the microstructure is refined. The friction coefficient of Mo-La₂O₃-Ni60a/SiC composite coating is 0.5, and the wear depth is 12.35 μm, 23% and 89% lower than that of 65Mn substrate, respectively. The surface roughness of the Mo-La₂O₃-Ni60a/SiC coating after wear is 2.06 μm, and the wear amount is 0.001 g. The wear mechanism of the coating is mainly adhesive wear, abrasive wear, and oxidation wear. The wear surface of the Mo-La₂O₃-Ni60a/SiC composite coating is mainly composed of micro furrows, accompanied by the generation of new wear-resistant layers.