Effect of CeO2 on Microstructure and Wear Property of Laser Cladding Ni-Based Coatings Fabricated on 35CrMoV Steel

The effects of CeO 2 addition on the macro-morphology, surface cracks, microstructure, precipitated phases and wear property of laser cladding Ni-based coatings on 35CrMoV steel were investigated by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscope (TEM), x-ray photoelectron spectroscopy (XPS) and friction and wear tester, respectively. The results indicated that the microstructure could be remarkably refined with the addition of CeO 2 . The width of eutectic structure is reduced from 1.74 μm to 237.5 nm with the amount of CeO 2 increases from 0 to 4.0 wt.%. Meanwhile, CeO 2 significantly decreases the number of the oxides and it can be obtained the minimal number of cracks when the CeO 2 addition reaches 4.0 wt.%. The main phase composition of Ni60 cladding layer is Ni 3 Fe, Ni 3 V, Cr 23 C 6 and Fe 5 C 2 . The distortional zone was observed around the eutectic of the coating. The average friction coefficient (0.438) and the wear resistance are the best when the addition of CeO 2 is 4.0 wt.%.