Iridite, also known as chemical conversion coating or chromate conversion coating, is a specialized chemical process used to treat the surface of various metals, particularly aluminum and its alloys. This treatment is typically carried out to improve corrosion resistance, increase adhesion, and enhance paint or coating durability.
The process involves immersing the metal object into an acidic solution containing chromate compounds, such as chromic acid. The acid reacts with the metal surface, forming a thin, protective layer composed of metal ions from the substrate and chromate ions. This layer, commonly referred to as an iridite coating, acts as a barrier against moisture, atmospheric pollutants, and other corrosive substances.
Iridite coatings not only offer corrosion protection but also provide a suitable surface for subsequent paint applications or other coatings, as they improve adhesion and promote bonding. Furthermore, these coatings can enhance the electrical conductivity of the metal, making them useful in applications where electrical conductivity or grounding is important.
Iridite is primarily used in industries such as aerospace, automotive, and electronics, where the metal substrates require effective corrosion protection and surface preparation for other finishes. It is often used as a pre-treatment process prior to painting, powder coating, or adhesive bonding.
Overall, iridite is a chemical conversion coating applied to metal surfaces, notably aluminum alloys, to enhance corrosion resistance, adhesion, and durability of subsequent coatings, making it a valuable process in various industries.
