Ni- P Electroless Coating of WC Powder and Evaluating the Effect of Powder Concentration in Bath and Pickling process

In this study the surface of WC powder particles coated by Ni-P electroless process and the effect of powder proportion immersed in Ni-P electroless bath and the activation pretreatment on the Nickel content was evaluated by X-Ray florescence analysis. To investigate the effect of powder proportion immersed in electroless bath, the activated powder with concentrations of 20 and 40 g/lit was added in electroless bath and the weight percent of Ni assessed to be 14/1 and 7/5% respectively. To evaluate the effect of activation process, WC powder with concentration of 20 g/lit was immersed in Ni-P electroless bath with and without activation process. By applying the activation process, the weight percent of Ni increased about 27%. An equation was proved to estimate the thickness of electroless layer. In this approach, the thickness of electroless layer in E20, E20P and E40P samples was calculated 0/08, 1/1 and 0/05 μm respectively. In XRD pattern of Ni-P coated WC, the W2C peaks were exhibited, because of the diffusion of hydrogen in structural defects.