Metal Finishing – Plating & Coating
Chemical Conversion Coating (Alodine)
Thin corrosion protection on aluminum that preserves electrical conductivity; for pre-paint surfaces and grounding interfaces. Cr+3 and Cr+6 options.
Process
A protective chromate layer formed chemically on aluminum (Alodine). Applied in Cr+6 and Cr+3 types. Provides corrosion resistance, improves pre-paint adhesion and preserves electrical conductivity.
What it provides
- Corrosion resistance
- Electrical conductivity preserved
- Paint adhesion performance
Frequently asked questions
What is the difference between Cr+6 and Cr+3 chemical conversion?
Hexavalent (Cr+6) is the classic yellow chromate with the highest corrosion resistance; trivalent (Cr+3) is RoHS compliant and colourless. MIL-DTL-5541 defines both as Class 1A (corrosion) and Class 3 (electrical conductivity).
Is chemical conversion enough under paint?
Yes. It is the standard pre-paint treatment on aluminium; the paint system is applied as primer and topcoat over the chromate.
Have a drawing for this process?
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