Nickel plating is mostly used as an undercoat for decorative chrome plating where its purpose is to bring desired gloss for the treatment and to protect the base material from corrosion. Nickel as such is also used in many objects. Nickel surface is hard, good looking, and gives a reasonable protection to the base material. Nickel coatings precipitated with different bath types differ widely in their properties.
Pinnoitus Helin Oy’s electric nickel plating solutions:
- Bath type: Watts, bright
- Barrel and rack
- Hardness: 150 HV
- Maximum dimensions of the object: 2700x900x250 mm
- Materials to be coated: aluminum, copper, steel, and their alloys
- Electroplated coatings of nickel for engineering purposes (ISO. 4526:2004)
- Electrodeposited coatings of nickel plus chromium and of copper plus nickel plus chromium (1456:2003)
- Electrodeposited coatings of nickel (ISO 1458:2002)
Semi-bright or sulphur free nickel coating gives better protection against corrosion than bright nickel plating. The inner tensions of semi-bright nickel plating are small, and thus its resiliency and elasticity are good.
Bright nickel plating has a lamellar structure. Additives are used to achieve the best possible smoothing effect and sharp gloss so that the mechanical grinding and polishing can be reduced or eliminated. Corrosion tolerance is not as good as with semi-bright nickel.
Double-layer nickel coating is a method where nickel is first precipitated from a semi-bright bath and then bright nickel on top of it. The layer containing sulphur is less precious than the sulphurless lower layer, and protects it cathodically. The combination gives very good protection against corrosion.
Satin nickel plating yields a pleasant and decorative surface that is suitable for many uses. The coating develops when small solid particles adhere into the coating along with nickel precipitation.
Black nickel plating creates a beautiful black surface. It is usually precipitated on top of semi-bright or bright nickel.