Zinc–Nickel Electroplating from Alkaline Electrolytes Containing Amino Compounds

As found from polarization curves, in alkaline solutions, depending on the potential sweep rate, the action of brighteners based on a polymeric tetraalkylammonium salt (PTAS) can decrease or increase the hydrogen evolution overpotential. In the presence of Zn(II) complexes, the inhibiting action of PTAS on the cathodic hydrogen evolution increases. Some PTAS-based brighteners that ensure production of Zn–Ni alloy coatings uniform in thickness and composition from alkaline electrolytes are proposed. The degree of alloying of Zn–Ni coatings can be controlled by modifying the electrolyte with amino compounds.