Applications for Nickel Plating
Applications for Nickel Plating
The nickel plating process is used extensively for decorative, engineering, and electroforming purposes because the appearance and other properties of electrodeposited nickel can be varied over wide ranges by controlling the composition and the operating parameters of the plating solution. Decorative applications account for about 80% of the nickel consumed in plating; 20% is consumed for engineering and electroforming purposes.
Decorative nickel plating solutions contain organic additives that modify the electro crystallization process so that mirror-bright, highly-leveled nickel coatings are deposited directly from the solution. Prior to the introduction of the "organic" baths, decorative nickel coatings were produced by polishing nickel-plated parts mechanically. Thin layers of chromium were electrodeposited over polished nickel coatings to prevent the "yellowing" or tarnishing of nickel in outdoor atmospheres, and that practice continues with the as-deposited bright nickel coatings now available. An effort to develop improved decorative, electroplated nickel coatings began in the late 1940s and led to the development of multilayer nickel coatings and micro discontinuous chromium coatings. Modern multilayer nickel coatings in combination with micro discontinuous chromium are capable of protecting and enhancing the appearance of most metals and alloys, plateable plastics, and other materials for extended periods of time.
Engineering applications of nickel plating include those where a fully bright appearance is not required. Engineering nickel deposits are usually sulfur-free and matte in appearance. These deposits may be specified to improve corrosion and wear resistance, to salvage or buildup worn or undersized parts, to modify magnetic properties, to prepare surfaces for enameling or for organic coating, to function as diffusion barriers in electronic applications, and for other purposes. Engineering applications exist in the chemical, nuclear, telecommunications, consumer electronics, and computer industries.