Generally, a chemical conversion coating is a coating produced by a chemical or electrochemical treatmentic on a metallic surface. The result of those processes is the addition of a superficial layer containing a compound of the metal. This process can be used either as a stand alone finish or as a base for subsequent paint.
Can be used as a primer for paint and has good adhesive properties for lamination. It also provides protection against corrosion and is an alternative to anodizing.