Chromate and Non Chromate Conversion Coating Services

Chromate conversion coating is a type of conversion coating that can be applied to passivate aluminum and zinc die casting components. The basic purpose is as a corrosion inhibitor, primer, decorative finish or to retain electrical conductivity.

NCP Conversion Coating for Aluminum Substrates 

Chromate conversion coatings on an aluminum substrate are known by the following terms: chemical film, yellow iridite,[5] and the brand names Iridite[5], Bonderite, formerly known as Alodine, in the UK, Alocrom).[7] It is also commonly used on aluminum alloy parts in the aircraft industry.


Iridite NCP is a non-chromium type of conversion coating for aluminum substrates. The most commonly referred-to standard for applying chromate conversion coating to aluminum is MIL-DTL-5541 in the US, in the UK it is Def Stan 03/18.


Gold Alodine

The process is named after the chromate found in chromic acid, also known as hexavalent chromium,[2] the chemical most widely used in the immersion bath process whereby the coating is applied. The treated component surface finish can usually be recognized by their distinctively iridescent, greenish-yellow color, hence the name gold alodine. However, hexavalent chromium is toxic, and it is non-RoHS compliant. In Europe, the RoHS (Restriction of Hazardous Substances) Directive is commonly referred to regarding the elimination of hexavalent chromium in electrical and electronic equipment.