Chromate conversion is a type of conversion coating that is applied to passivate aluminum, zinc, copper, silver, cadmium, magnesium, tin, and their alloys to slow down corrosion.
This process uses different lethal chromium compounds that can consist of hexavalent chromium.
Now the industry is developing less toxic alternatives to comply with the substance restriction legislation.
One option is the trivalent chromate conversion which is not as effective but is less damaging to the environment.
It is also generally used in aluminum alloy parts in the aircraft industry, where it is often called chemical film.
This has added value as a primer for the following organic coatings, as raw metal, particularly aluminum, is very difficult to paint or glue.
The chrome parts maintain their electrical conductivity to varying degrees, depending on the thickness of the coating.
This process can be used to add color for enhancement or identification purposes.
Chromate coatings are very smooth and jelly-like when first applied, but they harden and become hydrophobic as they age.
The curing process can be sped up by heating to 70 ° C, but very high temperatures will gradually damage the coating over time.
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