Pulsed Electrodeposition of Nano-Crystalline Ni with Uniform Co-Depostion of Micron Sized Diamond Particles on Annealed Copper Substrate

Nanocrystalline nickel was deposited on annealed copper substrate of unit surface area (1 cm 2 ) via pulsed electrodeposition technique using potentiostat (model 263A, Princeton Applied Research, USA) from Watts bath containing nickel sulfate, nickel chloride , boric acid and sodium citrate. Diamond particles of three different dimensions, viz., 1, 3, and 6 micron were added separately (5 g/L) to the watts bath and co-deposited along with nanocrystalline nickel. The temperature was kept constant at 55 °C. The solution was sonicated for 45-60 minutes prior to deposition to disperse the diamond particles uniformly in the bath. Depositions were carried out at different current densities, viz., 50, 100 and 200 mA/ cm 2 for different durations, i.e., 7, 14 and 21 minutes and best results are optimized for 200mA/cm 2 so it is used for all process here .Scanning electron micrographs(SEM) show uniform deposition of Microstructure of micron diamond on the surface of copper embedded in the nickel matrix. Elemental mapping confirmed uniform deposition of nickel and diamond with almost no cracks or pits. Mechanical properties such as, Vicker’s hardness and wear properties were investigated using microindentation, tribology and laser profilometry. Improved microstructural and mechanical properties were found in the case of electrodeposited surfaces containing followed by 3 and 6 micron diamond. The properties were also found better than those processed via stirring the solution during deposition.