Parametric Optimization of Process Parameters on the Response of Microhardness of Electroless Ni-P Coating

The present work deals with the synthesis of chemically deposited nickel-phosphorous (Ni-P) coating on copper substrate. The process parameters are optimized for maximum hardness based on L-27 Taguchi orthogonal design with three process parameters, viz., bath temperature, concentration of nickel Sulphate (a nickel source) and concentration of sodium hypophosphite (a reducing agent), respectively. This is considered and fitted into an L27 orthogonal array (OA) to find out the optimized condition for improved hardness of the coating. The optimized results were obtained from 35 g/L of Nickel Sulphate, 20 g/L of Sodium Hypophosphite and 90 degrees C of temperature. Analysis of variance (ANOVA) was performed to determine the significance of the individual process parameters. ANOVA showed that the factor Nickel Sulphate, the interaction between Sodium Hypophosphite and Temperature were significant in determining the hardness of the coating deposited in the optimized condition. The surface morphology, compositional and phase structure analysis of optimized sample are conducted with the help of scanning electron microscope (SEM), energy-dispersive X-ray analysis and X-ray diffraction (XRD) analyzer, respectively.