Kinetics of Contact Plating of Nickel on Aluminum from Alkaline Ammonia Solutions

Kinetics of the contact deposition of nickel on aluminum from alkaline ammonia solutions of different composition is studied by methods of voltammetry, gravimetry, and x-ray fluorescent analysis. It is shown that conventional voltammetric diagrams cannot be applied for determining the contact-exchange, current because they represent the net curve reflecting the conjugate processes of metal dissolution and cathodic hydrogen evolution. In connection with this, we propose determining the contact-exchange and aluminum dissolution rates from a cathodic voltammogram of a nickel electrode in the working solution.