Conversion Coating – (Chemical Film)
What is Conversion Coating?
Conversion coating (typically referred to as Chem Film) is a coating that can offer excellent surface corrosion resistance, increased paint adhesion capability, and corrosion protection at low electrical resistances.
What are the different types and classes of chem film?
Type I – Compositions containing hexavalent chromium.
Type II – Compositions containing no hexavalent chromium. (RoHS Compliant)
Note – If no material type is specified, type I will be used.
Class 1A – For maximum protection against corrosion on unpainted items, and increased adhesion on painted items. These coatings will generally be thicker and darker in appearance.
Used on tanks, tubing, and component structures where only exterior protection is required.
Class 3 – For protection against corrosion where low electrical resistance is required. These films are generally lighter in appearance, and of a thinner thickness in order to maintain low electrical resistance.
Used in electrical components such as circuit boards or connectors.
Which metals can chem film be applied to?
Chem film is typically used to enhance corrosion resistance of aluminum and beryllium. However, both zinc and magnesium are also feasible metals.