Investigation on in-situ synthesis of VC-WxC particulate reinforced Ni-based coatings by laser cladding

The VC-WxC particulate reinforced Ni-based coating was successfully in-situ synthesized by laser cladding on steel 45# substrates.The micro-structural and metallographic analyses were performed with a scanning electron microscopy,energy-dispersive spectrometer and X-ray diffractometer.The microhardness and wear-resistance of the coatings were investigated.It is indicated that a good finish VC-WxC reinforced composite coating can be reached at a suitable processing parameters.The microstructure at the bottom of the cladding layer mainly consists of oriented dendrites of γ(NiFe),and the microstructure at the center and upper zones contains VC,W2C,WC and Cr3C2 phase dispersed in the matrix of γ(NiFe)solid solution.The in-situ synthesized VC-WxC reinforced Ni-based coating gives very high hardness of HV0.3 1400 and excellent wear resistance,which is six times as that of Ni60 coatings.The results show that the improvement in hardness and wear resistance of the layer is due to the in-situ synthesis of VC,W2C,WC and Cr3C2,its homogenous distribution in the clad layer.