Saccharin Effects on Ni/Co Nanocrystalline Electrodeposited Coati ngs

A nancrystalline coating ofNilCo was deposited on a carbon steel substrate. This wasdone via electrodeposition in a Watts-type bath using direct current. The current density used was 12mAcm-2 • Grain size and characteristics of the coatings produced were investigated using various techniques including X-ray Diffraction (XRD), Electrochemical Impedance Spectroscopy (EIS) and Scanning Electron Microscopy (SEM). XRD patterns and Scherer fornmla were used to determine the grain size ofthe coated layer. Results obtained showed that the saccharin added to the bath decreases grain size. The effect of saccharin. (I g.rl ) as an additive for grain refining was investigated by (EIS). The EIS results showed that saccharin increases charge transfer resistance, and thus, decreases the surface diffusion of adions. It was also found that saccharin has a significant effect on decreasing the growth kinetics of grains and blocking the active sites of growth as well. Also, SEM observations revealed that saccharin inhibits pyramidal growth, and concomitantly reduces surface roughness and thus, increases surface brightness.

Keywords:

Electrochemistry , Ni/Co3 , Nanocrystalline coating , Electrodeposition , Saccharin