Monday, August 17, 2009

Satin Finishing of Nickel Plating

Satin nickel finishes are often desired, and traditionally have been obtained by mechanically scratch-brushing a nickel deposit before chromium plating. Besides the brushed or butler satin finish, there are satin like finishes obtained by blasting the plate with various types of particles. As already mentioned, hazy or satin finishes can be obtained directly from the bath by co-depositing fine nonconducting particles dispersed in semi bright or bright nickel plating baths and using plate thickness greater than about 2 µ. This type of satin nickel plate deposited on top of 10 to 15 µm of copper or semi bright sulfur free nickel, or even on top of bright nickel, was found to give outstanding corrosion protection in marine and severe industrial atmospheres.

Other method of obtaining satin and nonglare finishes directly from the nickel bath depend on the use of organic addition agents which produce low gloss instead of bright finishes. Satin finishes have also been obtained by the use of very fine dispersions or emulsions of organic compounds in semibright and bright nickel plating baths. Various low gloss satin like nickel chromium finishes are often used in combination with bright finishes for pleasing decorative effects. An important use is for an antiglare finish on automobile instrument panels.