ELECTROPLATING OF ZINC-NICKEL BINARY-ALLOYS FROM ACETATE BATHS

Zinc-nickel binary alloys have been successfully electrodeposited onto steel sheets from baths containing zinc acetate, nickel acetate and a cetic acid (pH 4.4-4.6). The potentiodynamic cathodic polarization, ca thodic current efficiency, morphology and composition of the deposits were determined for a variety of bath composition, temperature, curren t density and superimposed ne on dc. The baths are characterized by hi gh cathodic current efficiency for co-deposition. The co-deposition sh ows an anomalous behaviour with zinc being the preferentially deposite d metal. X-ray tests revealed the presence of a single gamma-phase (ri ch-zinc alloys) with body centered cubic structure. Copyright (C) 1996 Published by Elsevier Science Ltd.