ELECTRODEPOSITING COMPOSITE NICKEL LAYERS

摘要

An improved composition and process for producing a composite nickel-containing electroplate on a substrate including an inner nickel-containing layer of an average sulfur content of less than about 0.03 percent by weight, an intermediate nickel-containing layer of an average sulfur content of about 0.05 to about 0.5 percent by weight and an adjacent adherent outer nickel layer of an average sulfur content of about 0.02 to about 0.15 percent but less in sulfur than the intermediate layer and higher in sulfur than the inner layer. The controlled amount of sulfur is introduced into at least the intermediate layer by employing an aqueous acidic nickel solution containing a controlled amount of a thiazole compound so as to provide an intermediate nickel-containing deposit containing the specified average sulfur content.