Effect of CeO2 on the microstructure and microhardensss of laser-cladded Ni60 on 35CrMoV alloys

•The addition of CeO2 in Ni60 cladding layers significantly reduces the number of the oxide and proes.•The addition of 4 % CeO2 in Ni60 cladding layers has the minimal number of cracks.•XRD results show that the addition of CeO2 results in distorting lattice of Ni3Fe and Fe3Ni phase.•EDS results show that the addition of 4 % CeO2 produces the best element distribution uniformity.•4.0 % CeO2 in Ni60 cladding layers can refine the grains and evenly distribute the composition, thus improves the toughness of the cladding layer and reduces the microhardness of the cladding layer. In present work, the effect of CeO2 addition on the crack susceptibility, microstructure, phase composition, solute segregation and microhardness of Ni60 cladding layer was investigated. The coatings were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and microscopic vickers hardness tester. The results show that main phase composition of Ni60 cladding layer are Ni3Fe, Ni3V, Ni3B, Cr23C6, Fe5C2. The microhardness of the cladding layers from the surface to the substrate is gradually decreased with increasing depth of the cladding layer. With increasing addition of CeO2, the diffraction peak of XRD is shifted to the left, indicating the lattice distortion in the phases of the coating. Compared with other cladding layers with different contents of CeO2, the solute distribution of Ni60 cladding layer containing 4.0 % CeO2 is more uniform, and the cross-section structure is more compact and homogeneous. The results show that the addition of 4.0 % CeO2 can effectively inhibit the cracks and porosity, promote grain refinement, and improve the microstructure homogeneity in the Ni60 cladding layer.