Modeling the galvanostatic pulse and pulse reverse plating of nickel-iron alloys on a rotating disk electrode

A model incorporating mass-transfer effects, electrode kinetics, and homogeneous reaction is presented to describe galvanostatic pulse (PC) and pulse reverse (PR) plating of nickel-iron alloys from a sulfate bath onto a rotating disk elec trode. It has been satisfactorily fit to experimental data taken from the literature and then used to investigate the effects of pulse mode and pulse parameters and to compute the transient responses of the partial current densities and concentration profiles. A comparison of the effect of pulse mode on plating confirmed previously reported evidence that PC plating tends to produce alloys with similar iron content to those obtained by de plating, particularly at high current. PR plating has been shown to be the most effective method of controlling iron content in the alloys. By increasing the ratio df the anodic pulse amplitude to the cathodic pulse amplitude, the extent of anomalous codeposition and the sensitivity of alloy composition to the applied current can be reduced. Analysis of the transient partial current densities confirmed expert mental evidence that this improvement is due to preferential dissolution of iron during the anodic pulses.