NPFC - MIL-A-8625
ANODIC COATINGS FOR ALUMINUM AND ALUMINUM ALLOYS
|Publication Date:||30 June 1985|
This specification covers the requirements for three types and two classes of electrolytically formed anodic coatings on aluminum and aluminum alloys for non-architectural applications.
Types I and II.
The conventional Types I and II anodic coatings are intended to improve surface corrosion protection under severe service conditions or as a base for paint systems.... View More
Types I and II.
The conventional Types I and II anodic coatings are intended to improve surface corrosion protection under severe service conditions or as a base for paint systems. anodic coating can be colored with a large variety of dyes and pigments. Types I and II coatings provide better corrosion protection at higher cost than the chromite chemical conversion systems (MIL-C-5541). Repair of mechanically damaged areas by the use of materials conforming the MIL-C-5541 (see 3.3.5) will not restore abrasion resistance but provide and effective means of reestablishing corrosion resistance.
Type III. Type III coatings are intended to provide wear and abrasion resistant surfaces with improved corrosion protection due to greater thickness and weight than the conventional anodic coatings. Sealing of Type III coatings is not recommended unless corrosion resistance is also a factor. Wear resistance is reduced by sealing. Anodic coatings form an excellent base for most types of paint systems, adhesives and dry film lubricants. hard coatings may reduce fatigue strength. These factors should be considered in proposed use of parts subjected to cyclic loads. Generally, these hard coatings should not be used on parts or portions of parts which normally during rework would require restoring of dimensional tolerances because of wear of hard coated surfaces.View Less