Zinc-nickel alloy deposition in the presence of citrate ions

A new bath for zinc-nickel alloy electrodeposition has been studied using citrate as a complexant. Citrate ion was found to increase the zinc content of the alloy. Cyclic voltammetric studies were carried out to elucidate the effect of citrate ion in codeposition. The cathodic and anodic peaks indicate that due to efficient control of surface pH citrate ions cause depolarization during deposition. The absence of two cathodic peaks with decreasing nickel/zinc ratio reappeared in the presence of citrate ion. This led, not only to increased zinc content in the alloy, but also to reduced impurity content which affected the mechanical properties. This effect has been studied at varying zinc/nickel ratios and scanning potential ranges.