Chromate conversion coating has been used as a corrosion resistant coating on metallic substrates since the Second World War. It is a process that involves the conversion of the surface of a metal into a chromium compound. It is a corrosion-resistant inorganic coating that provides barrier protection to the substrate.
Chromate conversion coating is a chemical treatment process used on the surfaces of metal substrates to protect them from corrosion. It involves the conversion of the surface of the metal substrates into a chromium compound. Chromate conversion coating is a relatively quick, economical and easy process to apply.
Chromate conversion coating is usually applied through an electrochemical process that involves immersing the substrate in an alkaline chromate solution at a certain temperature for a predetermined time. A current is then passed through the solution to activate the chromate molecules. These ions are then attracted to the substrate, where they form cross-linked chromates. The coated surface develops adhesion and is highly corrosion-resistant.
Chromates are ideal for use in aerospace and automotive parts because of their excellent resistance to corrosion and their chemical and physical stability. The process can be used on various substrates, including aluminum alloys, steel, stainless steel and zinc alloys. However, chromate conversion coating is not appropriate for use on substrates that are prone to corrosion, such as copper, brass and bronze.
The application of chromate conversion coating requires strict control over the environmental conditions in order to achieve optimum results. The solution must be kept at the right temperature and with the right pH. The proper pH is important to ensure that the chromates form properly and that they adhesion to the substrate efficiently. Additionally, the operating temperature, current density, procedure and dwell time all need to be controlled in order to properly form the chromate film.
Chromate conversion coating provides excellent corrosion protection and chemical stability. It is ideal for parts that are subject to harsh environments, such as those found in aerospace and automotive applications. Chromate conversion coating is relatively easy and cost-effective to apply, and can be used on a variety of substrates. As such, it is a popular coating solution for a variety of industrial applications.
