The coating of TiC layer on the surface of nickel by electric discharge coating (EDC) with a multi-layer electrode

Multi-layer electrodes (MLEs) are proposed in this study to coat a titanium carbide (TiC) layer on the surface of a nickel workpiece by electric discharge coating (EDC). The MLE is composed of titanium (Ti) and graphite (Gr) layers with the same dimensions stacking alternately. Both of this new type of electrode and the conventional electrode, the bulk type, are compared in this study. The experimental results indicate that the Gr layer of the MLE may enhance the concentration of carbon element locally. Also, carbon element with high concentration could increase the combination of Ti and carbon (C) to become TiC, enhance surface hardness of the coated layer, decrease surface roughness of the coated layer, reduce formation of microcracks, and enhance the stability of electric discharge and coating speed.