What is conversion coating?
An SAF Conversion Coating is a proper corrosion resistant aluminum surface treatment for painting, powder coating, and adhesive bonding. Alodine, Alocromin, and Iridite are trade names sometimes applied to these coatings.
These coatings are applied through an immersion process and are compatible with most aluminum alloys.
Non-chrome coatings are often specified where environmental considerations are paramount. Chrome conversion coatings provide an extra measure of corrosion resistance and can also be used as a standalone finish.
SAF Conversion Coating Uses
- Military specification MIL-DTL-5541, ISO 8081:1985.
- Tesla Technical Specification (TS- 0002074)
- Ford Arizona Proving Ground Equivalent (APGE) corrosion test FLTM BI 213-01 at 15 and 30 cycles on specified alloys.
- General Motors – GMW16721 Aluminum Pre-treatment to Support Structural Adhesive Bonding
SAF contains in-house facilities for lap shear testing and APGE aging of adhesive bonded aluminum. We have developed extensive experience in testing for aluminum adhesive bonding applications in the transportation industry.
Conversion Coating Background
Conversion Coatings are sometimes called “chrome phosphate” coatings. SAF non-chrome, or chrome-free coatings meet many industry standards.
There are many kinds of conversion coatings, some based on chrome and some used with other metals.
SAF offers quality conversion coating for aluminum, including a very strong bath required for final finish applications, including those required to meet military specifications. They are commonly used on aluminum alloy parts in the aircraft and automotive industries.Conversion coating, which is a chemical reaction to a base metal, is a passivation or passivating technique for strengthening and preserving the appearance of metals (others include microcoating and spontaneous oxidation in the air). A chromate conversion coating on an aluminum substrate is a chemical film.