Alodine / Chem Film Coating
Chromate conversion coating that provides corrosion protection and an excellent base for paint adhesion on aluminum — widely used in aerospace, defense, and electronics applications.
Process Overview
MIL-DTL-5541 Compliant
Class 1A for maximum corrosion protection. Class 3 for low electrical resistance where conductivity must be maintained.
Aerospace Standard
Required finish for many aerospace aluminum components before assembly. RoHS-compliant trivalent chem film available.
Thin Coating
Minimal dimensional impact — ideal for tight-tolerance parts where anodizing thickness would affect fits.
Specifications
| Parameter | Specification |
|---|---|
| Standard | MIL-DTL-5541 Type I & II |
| Class 1A | Maximum corrosion protection (gold/iridescent) |
| Class 3 | Low electrical resistance (clear) |
| Coating Thickness | 0.4–4.0 μm (negligible dimensional change) |
| Base Material | All aluminum alloys |
Compatible Materials
- Aluminum 6061
- Aluminum 7075
- Aluminum 2024
- Aluminum 5052
- Aluminum castings
Applications
- Aerospace structural parts
- Defense electronics chassis
- Aircraft interior fittings
- Pre-paint aluminum components
- Electrical grounding surfaces
Frequently Asked Questions
Alodine vs anodizing — which should I choose?
Alodine for thin coating with minimal dimension change, conductivity requirements, or as a paint base. Anodizing for thicker, harder, more durable wear-resistant surfaces.
Is trivalent chem film RoHS compliant?
Yes — we offer RoHS-compliant trivalent chromium chem film (Type II) as an alternative to hexavalent chromium (Type I) for EU and environmental compliance.
Can Alodine be applied over machined surfaces?
Yes — parts should be free of oils, burrs, and heavy oxidation. We degrease and prepare surfaces in-house before chem film application.
Need Alodine / Chem Film on Your Parts?
Upload your drawings and specify your finishing requirements — we'll quote machining and finishing together within 24 hours.
Request a Quote