Conversion Coating (Chem-Film)

Definition: Chromate conversion, also known as chemical film, alodine or iridite, offers increased corrosion protection on aluminum. It is inexpensive, electrically conductive and is often used as a pre-treatment for paint and adhesives. Chromate can be used as a standalone finish or as a post treatment over other metal plating finishes.

Benefits

  • Improve adhesion for post coatings
  • Corrosion resistance
  • Remains electrically conductive

Specifications

  • IL-DTL-5541 Type I & II, Class 1A & 3
  • MIL-C-5541 Class 1A & 3

Classifications

  • Type I-Compositions containing hexavalent chromium (typically yellow in appearance)
  • Type II-Compositions containing no hexavalent chromium (typically clear in appearance)
  • Class 1A-For maximum protection against corrosion, painted or unpainted
  • Class 3-For protection against corrosion where low electrical resistance is required

Available Processes

  • Hand-line
  • Hoist-line (Automated, Large Capacity)

Notes: JMD can provide corrosion testing according to ASTM B117 per request. JMD offers both RoHS compliant and non RoHS compliant chemical conversion coatings.