Microstructure of mechanical vibration assisted laser remelting Ni-based alloy and TiC composite coating

NiCrBSi+TiC composite coating was fabricated by mechanical vibration assisted laser remelting hybrid modification process on 45 steel substrate surface. The morphology, microstructure and phase constitution of the composite coating were characterized by scanning electron microscopy (SEM), energy dispersive spectroscope(EDS) and X-ray diffraction(XRD), respectively. Microhardness distribution of the composite coating was also analyzed. Results indicate that the matrix is changed from dendrites to cellular dendrite. The TiC particles and other reinforced phase shows an increasing trend, the area fraction in the field of view increases by 18.2%. The diffusion of Ti element exhibits a decreasing trend. The crystallization strength and dispersion strengthening are improved due to the influence of the combination of laser rescanning and vibrating force. The microhardness fluctuations trend of the mechanical vibration assisted laser remelting coating slows down in the interface. Mechanical vibration can improve effectively the transverse microhardness fluctuations of the bonding interface zone.