ELECTROPLATING OF ZINC-NICKEL BINARY ALLOYS FROM ACETATE BATHS

Abstract Zinc-nickel binary alloys have been successfully electrodeposited onto steel sheets from baths containing zinc acetate, nickel acetate and acetic acid (pH 4.4–4.6). The potentiodynamic cathodic polarization, cathodic current efficiency, morphology and composition of the deposits were determined for a variety of bath composition, temperature, current density and superimposed ac on dc . The baths are characterized by high cathodic current efficiency for co-deposition. The co-deposition shows an anomalous behaviour with zinc being the preferentially deposited metal. X-ray tests revealed the presence of a single γ-phase (rich-zinc alloys) with body centered cubic structure.