Study of the effect of new brightener on Zn-Ni alloy electrodeposition from acid sulphate bath

The electrodeposition of Zn-Ni alloy from acid sulphate bath was carried out in presence of a brightener, such as condensation product of vanillin and serine (VS). The cyclic voltammetry and chronoamperometry techniques were used to study the nucleation mechanism process, while polarization and electrochemical impedance spectroscopic (EIS) techniques for corrosion studies. The model of Scharifker and Hills was used to analyze the current transients and it revealed that Zn-Ni electrocrystallization process in presence of VS, under the studied conditions, is governed by progressive nucleation process. Corrosion studies showed that bright Zn-Ni alloy coatings exhibited higher corrosion resistant nature. The Zn-Ni layer obtained in presence of VS shows smooth morphology with smaller grain sizes and higher percentage of reflectance signals.