A comparative study of the structure and wear resistance of NiCrBSi/50 wt.% WC composite coatings by laser cladding and laser induction hybrid cladding

NiCrBSi/50 wt.%WC composite coatings were produced on carbon steel via laser cladding (LC) and laser induction hybrid cladding (LIHC).The microstructure and phase constituents of the composite coatings before thy sliding wear and the wear behavior were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Under the same laser processing parameters, the cladding height during LC was much higher than that during LIHC, whereas the dilution, cladding width, heat-affected-zone (HAZ) and efficiency of powder utilization during LC were much smaller than those during LIHC. Additionally, WC particles suffered from more severe heat damage during LIHC compared with those during LC, resulting in the precipitation of herringbone, dendritic and blocky carbides and inhomogeneous distribution of WC particles in the composite coating. However, the increase of the laser scanning speed during LIHC decreased the heat damage of WC particles, improved the homogenous distribution of WC particles and further increased the microhardness of the binder metal, which in turn led to an increase in the wear resistance of the composite coating. (C) 2016 Elsevier Ltd. All rights reserved.