Zinc Nickel Plating combines both zinc and nickel to form a protective layer on metal surfaces. Zinc Nickel Plating provides excellent corrosion resistance, generally five times better than pure zinc. It possesses the highest abrasion resistance of all zinc alloys and has outstanding covering power for deep recesses. Chromate conversion coatings and post treatment sealers can be added to further increase the longevity of the finish. Available in both rack and barrel processes, Zinc Nickel Plating is an environmentally friendly replacement for the the toxic metal cadmium.
Zinc Nickel coatings can be deposited utilizing an alkaline (non-cyanide electrolyte or an acide (chloride) electrolyte. The choice of electrolyte impacts product appearance and performance as outlined below.
Alkaline Zinc Nickel Plating Systems operate at 30-50% efficiency and have the advantage of producing uniform thickness and nickel distribution across a wide current density range. The deposit has good ductility and can be used on parts requiring post plate forming. The inherent alkalinity of the bath reduces the post plating corrosion tendency of unplated surfaces such as interior diameters of tubular components.
Acid Zinc Nickel Plating Systems deposit faster and have efficiencies two to three times higher than Alkaline Zinc Nickel Plating Systems. As a result of these higher efficiencies, Acid Zinc Nickel can be deposited directly over a wide range of metallic substrates. Deposits generated by these systems exhibit substantially higher variation in plate thickness and alloy composition as compared to Alkaline Zinc Nickel.