Anodic Oxidation Coloring Aluminum
Anodizing is an electrochemical conversion process that forms a protective oxide film on the surface of aluminum parts. The process is widely used to prevent corrosion of aluminum and enhance the surface wear resistance and surface look of the aluminum parts. It is also a convenient method to color the aluminum components. The colored aluminum parts can be widely used in various fields, such as decorations, handicrafts, aerospace and other industries.
Under normal circumstances, the anodic oxidation is carried out when the aluminum parts are immersed in the acidic electrolyte solution, and then the electricity is passed to the aluminum parts, so that the aluminum surface is made of aluminum oxide. First, the surface of the aluminum before anodizing must be cleansed. False oxide films and oil stains can be removed from the aluminum surface by using various degreasing solutions or mechanical methods. Then, the aluminum should be etched to make its surface textured. The acid or alkali solutions or high-frequency electrolytic etching can be used for different aluminum alloys.
After the surface treatment, the aluminum parts are put into the electrochemical hardening tank to start anodic oxidation coloring. The tank is filled with an acidic colored electrolyte, which is usually composed of sulfuric acid, phosphoric acid and metal salt, etc. Different metal salts can produce different colors when they interact with the metal. After immersing in the electrolyte and passing the current to the metal, metal oxide film with bright and uniform color will form on the metal surface in the chemical reaction, which makes aluminum parts look very beautiful.
In order to ensure the quality of anodic oxidation coloring, the aluminum parts should be quenched after anodizing to remove the hydrogen from the oxide film, and then passivating agents can be used to protect aluminum from corrosion. The passivation film will also give the anodic oxidation film a uniform surface and an ideal appearance. Finally, the anodizing film should be sealed to enhance its durability, which can effectively reduce the chance of corrosion of aluminum surface. Anodizing coloring aluminum parts is one of the most widely used methods for coloring aluminum parts and will become increasingly important in the future.
To sum up, anodic oxidation coloring aluminum is a more and more popular surface treatment technique. It is not only a durable and protective process, but also a convenient way to color aluminum parts, which makes them look more attractive and durable. In addition, it helps to enhance the corrosion resistance of aluminum components, and can be widely applied in various fields.
