Aluminum alloys form a passivation film on the surface under normal use environment, and have the function of protecting metals from corrosion.
Conversion treatment (so-called alodine treatment) may be performed for the purpose of improving appearance and corrosion resistance. The chemical conversion-treated surface is also used for painting substrate due to its good adhesion.
Alodine treatment is a chemical conversion treatment using hexavalent chromium, the use of which is currently restricted. We perform chemical conversion treatment using environmentally friendly trivalent chromium.
|Wear resistance||Heat resistance||Corrosion resistance||Chemical resistance||Decorativeness||Lubricity||Adhesion||Electrical conductivity||Dimensional accuracy|
Improved corrosion resistance with chemical conversion film.
The corrosion resistance of aluminum can be improved by chemically forming a corrosion resistant film that is superior to the natural oxidation of aluminum.
The material data catalog states that it is MIL-5541 compliant (SST 336 hours or more).
The chemical treatment film weight listed in the catalog is 0.25 g / m2, which conforms to ASTM 449 Class 2.
Aluminum Chromate Conversion Coatings to ASTM B449-93
Class Appearance Coating Mass (g/m2) Corrosion Protection
1 Yellow to Brown 0.4 to 2 g/m2 Maximum as Final Finish
2 Colorless to Yellow 0.1 to 0.4g/m2 Moderate as Paint Base
3 Colorless < 0.1 g/m2 Decorative, Slight
4 Light Green to Green 0.2 to 5 g/m2 Moderate as Paint Base
Excellent dimensional accuracy
The conversion treatment film is a very thin film, unlike the metal film obtained by plating. Therefore, it is a suitable process when you'd like to avoid dimensional changes.
This treatment is perfect when you want to improve the corrosion resistance without changing the aluminum characteristics.
The conductivity of the film is 0.8 mΩ / cm2 (according to the chemical catalog).
|Processing type||Maximum size||Maximum weight|
Aluminum materials, aluminum die casting.