ANOMALOUS ELECTRODEPOSITION OF ZINC-NICKEL ALLOYS FROM AQUEOUS CITRATE BATHS

The electrodeposition of Zn-Ni alloys onto steel substrates from acidi c citrate baths has been investigated. The potentiodynamic cathodic po larization and cathodic current efficiency were measured under some op erating conditions. The results show that the electrodeposition of Ni is obviously inhibited by the presence of Zn2+ ions. Consequently, Zn- rich alloys were obtained indicating anomalous type of codeposition wi th indicating anomalous type preferentially deposited metal. The morph ology of the as-plated alloy was examined using a running electron mic roscope (SEM) while the structure of the alloy was examined using both the X-ray diffractions and anodic stripping voltammetric (ASV) techni ques.