Kinetics of contact plating of nickel on aluminum from alkaline ammonia solutions

Kinetics of the contact deposition of nickel on aluminum from alkaline ammo nia 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-exchan ge, current because they represent the net curve reflecting the conjugate p rocesses of metal dissolution and cathodic hydrogen evolution. In connectio n with this, we propose determining the contact-exchange and aluminum disso lution rates from a cathodic voltammogram of a nickel electrode in the work ing solution.