POTENTIOSTATIC DEPOSITION MODEL OF IRON-NICKEL ALLOYS ON THE ROTATING-DISK ELECTRODE IN THE PRESENCE OF ORGANIC ADDITIVE

A mathematical model has been developed to describe the electrodeposit ion of Fe-Ni alloys in the presence of an organic inhibitor. The model includes the mass transport of participating ionic species, homogeneo us chemical reactions within the diffusion laver, the metal hydroxyl i on and inhibitor adsorption, and the associated electrochemical kineti cs. The model can be used to predict the iron-nickel deposition rate ( iron and nickel content in the alloy) as a function of the disk rotati on speed, solution pH. and the bulk concentrations of the electroactiv e species and the organic additive. Model results indicated that in th e presence of organic additive (saccharin) higher ferrous ion and nick el ion concentrations can be preserved at the interlace without concen tration depletion within the diffusion layer. The model also predicted that iron content in the alloy increases by increasing the concentrat ion of the additive and by increasing the electrolyte pH and disk rota tion rate.