An Investigation on Pulse Current Nickel Plating on Copper Substrate

The synthesis of micro and nano sized nickel crystals by electrodeposition has been studied for more than a decade now. A lot of attention is being spent on controlling the process parameters, adjusting the bath composition and developing new additives for the developing a good quality coat. In this paper bulk nanocrystalline nickel was developed on copper substrate using pulsating current supply. Pulse current was applied at a cycle time of 240 sec, 50% duty cycle and 0.00417 Hz frequency. Surface morphologies, grain sizes, textures and hardness were studied for different pulses with varying peak current. Energy Dispersive Spectroscopy (EDS) results represents a good layer of nickel coating developed on copper substrate. Coating weight and thickness is observed to increase with rise in peak current. Microstructure captured by Field Emission Scanning Electron Microscopy (FESEM) technique represented a uniform coating developed comprising of primary (fine) and secondary (coarse) granules of nickel. The hard primary and secondary granules deposited on the surface of the copper substrate tends to increase the hardness. From the results it is observed that there is about 8% increase in hardness of nickel pulse plated sample compared to copper substrate. Nickel coating on copper is largely used for copper mould applications in continuous casting process.