Microstructure and properties of laser cladding <i>in-situ</i> ceramic particles reinforced Ni-based coatings
Guixin Liu, Hanguang Fu
Abstract
Abstract In order to explore the effect of in-situ ceramic particles on the microstructure and properties of nickel-based composite coatings, the nickel-based coatings reinforced by the in-situ ceramic were prepared on the surface of 40CrNiMo steel using laser cladding technology. On the basis of NiCrBSi (Ni45) powder, 0 wt%, 5 wt%, 10 wt%, 15 wt%, and 20 wt% of B 4 C and ferrovanadium (FeV50) were added, which the atomic ratio of V to C was 1:1. Microstructure and phase analysis were carried out by metallographic microscope (OM), X-ray diffractometer (XRD), and scanning electron microscope (SEM). The results show that the NiCrBSi coating without B 4 C and FeV50 are mainly composed of γ-Ni, Cr 23 C 6 , Cr 7 C 3, and CrB phases. After adding B 4 C and FeV50, the matrix is mainly composed of γ-Ni(Fe) solid solution, and strengthening phases such as CrB 2 and VB 2 appear in the coating. With the increase of the B 4 C and FeV50, the amount of CrB 2 and VB 2 increased, and the hardness and wear resistance were improved. When the addition amount of B 4 C and FeV50 is 10 wt%, the in-situ reinforced particles were uniformly distributed and the wear resistance of the coating was the best and was about 15 times that of Ni45 coating.