What does conversion coating do?

Conversion coatings are formed by chemically or electrochemically transforming the elemental composition of the metal surface. This coating can function as a stand-alone corrosion protection coating and/or as an adhesion layer for the succeeding organic coating.

What is alodine conversion coating?

Also known as chem film or chemfilm, Alodine® is a chromate conversion coating that protects aluminum and other metals from corrosion. Related products include Iridite®, TCP-HF, and Bonderite®.

How does chromate conversion coating work?

Chromate conversion coatings are obtained by chemical reaction with the metal being treated, to form a complex chromate film over the entire surface. The coatings can be applied to aluminium, zinc, cadmium and magnesium.

Is zinc phosphate a conversion coating?

Phosphate conversion coating is a chemical treatment applied to steel parts that creates a thin adhering layer of iron, zinc, or manganese phosphates, to achieve corrosion resistance, lubrication, or as a foundation for subsequent coatings or painting. It is one of the most common types of conversion coating.

Can you conversion coat stainless steel?

Black oxide, historically called browning or bluing, is a conversion coating most often used for steel and stainless steel that is very similar to the alodine process for aluminum. Over many millennia of existence, a variety of procedures have been developed for applying black oxide finish.

What is the primary purpose for applying chromate conversion coatings to cadmium?

When chromate conversion coating is applied, its purpose is to passivate metal substrate, preventing oxygen in air to corrode the metal surface. Chromate conversion coating is used on metals such as aluminum and zinc, and to a lesser extent copper, cadmium, silver, tin, and other metals and their alloys.

What is the difference between chromate and chromium?

Chromium and chromate are different compounds. Chromium is represented as Cr and chromate is represented as CrO42-.

Is iron phosphate a conversion coating?

One of the most popular and effective forms of pretreatment for steel is iron phosphate. Iron phosphate is a conversion coating that provides a barrier against oxidation. It is most effective on bare (uncoated), clean steel.

What is the difference between zinc phosphate and manganese phosphate?

Zinc phosphate coatings (Type Z) are also available and are mainly used for rust proofing on ferrous metals. They can be applied by immersion or spraying. Zinc phosphate is a lighter alternative to manganese phosphate, while providing resistance to harsh elements that tend to wear products quickly.