Investigation of surface characteristics and effect of electrodeposition parameters on nickel-based composite coating

In this work, metallic deposition with the help of electrochemical energy is performed with the in-house fabricated experimental set-up. Controlled deposition of nickel and graphite was carried out while varying electrodeposition process parameters namely, bath temperature, deposition time, current density, etc. to achieve optimum condition. The effects of graphite particles on surface morphologies, compositions, coating thickness were investigated by optical microscopy, SEM, EDS, and XRD. Results of XRD and SEM images show that graphite particles have been dispersed uniformly throughout the substrate. Optical microscopy images show the uniform average thickness with excellent surface finish which can be achieved at optimized process parameters such as; 10-minute deposition time, 4.0 pH value of the solution, 8-10 A dm-2current density, and 40° C bath temperature under specific stirring condition. Further, thermal conductivity and tensile strength of electrodeposited sample have been evaluated. Thermal conductivity of the developed coated substrate is found to be greater than that of the platinum, Al-Ni alloys and silicon nitrides and hence it can be envisioned as potential substrate as micro heaters used in MEMS based applications.