In contrast with electroplating, electroless nickel (EN) does not require rectifiers, electrical current or anodes. Deposition occurs in an aqueous solution containing metal ions, a reducing agent, complexing and buffering agents and stabilizers. Chemical reactions on the surface of the part being plated cause deposition of a nickel alloy
Since all surfaces wetted by the electroless nickel solution have the same plating rate, the deposit thickness is quite uniform. This unique property of EN makes it possible to coat internal surfaces of pipes, valves and other parts. Such uniformity of deposit thickness is difficult, if not impossible, to achieve by any other metal finishing method
The discovery of electroless plating is credited to Brenner & Riddell in the 1940’s. Today EN has grown into a very substantial segment of the metal products finishing industry
Compared with plating of other metals, electroless nickel (EN) plating is relatively young-being commercially available for less than 50 years; however, in the past decade the usage of the coating has grown to such proportions that electroless nickel plated parts are found underground, in outer space, and in a myriad of areas in between