1. SCOPE
1.1 Scope. This specification covers chemical conversion coatings formed by the reaction of chemical conversion materials with the surfaces of aluminum and aluminum alloys.
1.2 Classification. The chemical conversion coatings are of the following types and classes.
1.2.1 Types. The chemical conversion coatings are of the following types (see 3.1):
Type I – Compositions containing hexavalent chromium. Type II – Compositions containing no hexavalent chromium.
1.2.2 Classes. The materials, which form protective coatings by chemical reaction with aluminum and aluminum alloys, are of the following classes (see 6.1 and 6.4).
Class 1A - For maximum protection against corrosion, painted or unpainted.
Class 3 - For protection against corrosion where low electrical resistance is required.