Zinc–nickel codeposition in ammonium baths

Zinc–nickel alloys were obtained from ammonium chloride baths. The best Ni2+ and Zn2+ concentrations from the plating baths were mainly selected using electrochemical stripping techniques. The alloys obtained from the selected bath had about 13% Ni, a good appearance and a very good corrosion resistance. The corrosion behaviour was further improved by adding saccharin. Electrochemical, XPS and TEM results indicated that the composition of the alloys obtained without additive was not uniform along the deposit depth. The addition of saccharin led to much more uniform deposits.