The Influence of Mechanical Properties of Laser-Melted Tungsten Carbide Composite with Nickel/Cobalt Ingredients

The aim of this study involved the optimisation of the processes of laser cladding using statistical tools to improve the mechanical properties of the clad WC/Co/Ni deposits and to obtain the required weld for practical applications. The effect of laser cladding parameters on wear properties of welds was determined by using orthogonal array tests and analysis of variance. It was found that Co content, Ni content, laser power and scanning height were significant factors affecting WC/Co/Ni welds. In addition, the significant factor in response surface method was used to construct the response surface model based on the data from the orthogonal array experiment that was designed by Taguchi. The experimental results showed that a look at the microstructural evolution shows that white initially precipitated carbides are present, grey areas are WC mixed with Co and Ni compounds, meanwhile, the wear structure is an internal extension of unmelted WC, with greater plastic deformation in the Co-based alloys, and to a lesser extent in the Ni-based alloys, and even smaller plastic deformation in the WC-Co-Ni alloys. By adding nickel/cobalt alloys, the composite coating extension is seen to have good anti-wear performance. Based on the regression model of the wear by laser cladding, a pairwise interaction model in RSM was developed, which was further deepened to develop a three-dimensional contour pairwise interaction model of the wear behaviour. The results show that the predicted values of the RSM for wear performance are very close to the experimental data, which proves the effectiveness of the Taguchi design-based RSM in improving the mechanical properties of laser cladding.