Influence of process parameters on Electrodeposited Ni-Al₂O₃ composites by conventional and sediment type of co-deposition by Grey Scale Analysis

Madhan Gopal M M, Vishnu P S, Jeyaraj S, Arulshri K P

Ni-Al₂O₃ composites are prepared over a mild steel specimens using electrodeposition method. The coatings are prepared by conventional and sediment type depositions using watts type nickel with Al₂O₃. Three primary plating parameters are considered for electro-deposition, namely current density, temperature of the bath, particle concentration in bath with three levels for both conventional and sediment type depositions. L-9 orthogonal array of taguchi design is chosen for experimental design. The deposited coatings are examined with optical microscope, SEM micro graphs, XRD and EDX investigations to confirm the deposition. The influence of parameters on micro hardness of electro-deposition was investigated with signal to noise ratio analysis for both conventional and sediment type deposition. It is inferred that current density and temperature of the bath has a sound effect on micro hardness of coating by conventional type of deposition whereas temperature of the bath and particle concentration has a major effect on micro hardness of coating by sediment type of deposition. Grey scale analysis was employed to indentify the significance of process parameters and optimization of process parameters for the better micro hardness values.