Microstructure evolution and wear resistance of in-situ synthesized (Ti, Nb)C ceramic reinforced Ni204 composite coatings

Poor mechanical properties of Ni alloy hinder its widespread application in the industrial. In order to enhance its performance, Ni204-based composite coatings reinforced with in-situ TiC and (Ti, Nb)C particles were investigated and successfully built on 45 steel alloy via laser cladding technology. The strengthening phase characteristics, microstructure evolution, and mechanical properties of the samples were examined and analyzed. By doping Ti and C particles into the NbC–Ni composite coatings, the large lump structure of NbC was effectively eliminated. The alternative formation of TiC and NbC promoted the in-situ generation of the multiphase (Ti, Nb)C and further prevented the NbC from agglomerating. Therefore, the problem of TiC particles floating has been effectively alleviated. The microhardness is up to 1.53 higher than that of the original Ni204 coating. Compared with the mass fraction ratio of Ti/C/NbC is 7:2:21 composite coating, the wear resistance of the composite coating (the addition of NbC is 30%) is improved by around 11 times. The composite coating has excellent combination property when the mass fraction ratio of Ti/C/NbC is 4:1:5. This work provides insight into the Ni204-based composite coatings by ceramic reinforcement.