The chemical conversion of aluminum and aluminum alloys is formed by the direct reaction of the aluminum surface with the chemical oxidant in the solution. This process does not require an applied voltage, also known as chemical oxidation treatment. Chemical conversion can be divided into two categories: alkaline and acidic according to the nature of its solution, and according to its film properties, it can be divided into oxide film, phosphate film, chromate film and chromate-phosphate film. The film layers obtained are collectively referred to as chemical conversion films.
The chemical conversion film is widely used. In addition to its general protective effect, the conversion film obtained by some process formulas also has a decorative effect (the surface needs to be coated with varnish), and some can improve the combination with the coating. Strength; some of them can still maintain the original conductivity after chemical conversion treatment, so the film is also called conductive conversion film.
Chemical conversion treatment process is easy to operate, simple equipment required, high production efficiency, low production cost, the obtained conversion film has a wide range of applications, and is a coating variety with broad prospects and popularization value.