The anodizing process can only be performed on aluminum and its various alloys.
Anodizing is not an applied coating; there is an actual penetration of aluminum and a build up on the surface of an oxide layer. Aluminum naturally forms a very thin layer of oxide; the anodizing process provides a much thicker and controlled coating. The anodizing process consists of giving aluminum parts an electrical charge while submerged in an electrolyte bath. At the beginning of the charge the formation of the oxide film begins to form on the surface. Anodic coating pentrates and grows equally on the aluminum part. This is one of the main reasons for durability of anodizing.
The anodic coating can be dyed for cosmetic purposes, as well as for the purpose of color coding of parts. The dye is absorbed into the pores of the anodic coating. The parts can be sealed or left unsealed for further processing, ie., painting, teflon application,e-coating. Also available is a hot water seal, used for sealing clear parts on customers request.
There are five dye baths, all with high rating of lightfastness.
Aluminum oxide is the third hardest element known. Anodizing embodies the natural-occurring property into aluminum. The harder surface on the aluminum,
after the anodizing process, has proven to have a variety of useful applications.