Tech: Alodine Clear / Iridite Clear
Iridite Clear (Chem Film – DTL-5541 Type II)
Iridite Clear, also known as chromate conversion coating or “chem-film”, is a protective film applied to aluminum and its alloys. Here are the key points:
Purpose:
Provides corrosion protection.
Acts as an adhesion promoter for paint or adhesive bonding.
Conductive (typically no more than 5 milliohm resistance).
Coating thickness: 10-40 millionths of an inch.
Process:
RoHS and WEEE compliant.
Application methods: dip, brush, swab, or spray.
The coatings range from clear to dark yellow (Clear is ROHS compliant) .
Regulations:
Iridite NCP and Alodine 5200 are hexavalent-chrome-free alternatives.
Used in auto industry (brake calipers, electrical components) and aerospace (paint and primer application).
Specifications:
MIL-DTL-5541 (formerly MIL-C-5541)
ASTM B449 (Hexavalent Chromate)
ASTM B921 (Non-Hexavalent)
AMS 2473 (General Purpose Applications)
AMS 2474 (Low Electrical Resistance
Applications).