Electroless nickel plating is depositing a uniform, dense nickel coating on the surface of plating pieces by electrolysis. The plating pieces are placed in the electrolyte that consists of nickel salt (called the main salt), conductive salt, pH buffer and wetting agent, with nickel metal as the anode, plating pieces as the cathode and a DC power source. Sulfate-chloride solutions containing some of the chloride, called "Watts" nickel baths, are the most widely electrolyte used in production.
If brighteners like sodium naphthalene disulfonate, saccharin, coumarin and p-toluene sulfonamide are added in the plating solution, a bright nickel coating can be obtained directly.
Nickel plating layer is bright, corrosion-resistant and wear-resistant. Nickel plating solution is easy to maintain. The wastewater treatment is simple. So, nickel plating is the preferred plating for protective decoration coatings and some functional coatings.