Anodic oxidation, electrochemical oxidation of metals or alloys.Aluminum and its alloys are formed on aluminum products (anodes) with an oxide film due to the addition of current to the corresponding electrolyte and specific process conditions.
In order to overcome the aluminum alloy surface hardness and wear resistance of defects, and expand the application scope, prolong service life, surface treatment technology to become an indispensable part of aluminum alloy, and the anode oxidation technology is currently the most widely used and most successful.
With the continuous innovation of manufacturing process, the "surface article" requirement for surface treatment of workpiece is also getting higher and higher.Anodizing is the product of this era.She has the characteristics of fast processing, low cost and good effect., of course, all this is completely based on workpiece surface treatment conditions, the workpiece surface processing and the ultrasonic cleaning is one of the most thorough way, so there are anodized ultrasonic cleaning machine.
The oxide film obtained by anodic oxidation process is generally 5-20v m, and the thickness of hard anodic oxide film can reach 60-2500m. The film layer also has the similar characteristics:
(1) high hardness.The anodic oxide film is not only of high hardness, but also has good abrasion resistance. Especially, the porous oxide film has the ability to absorb lubricant, which can further improve the abrasion resistance of the surface.
(2) have higher corrosion resistance. This is because the composition of alloy inclusions or metal compounds cannot be oxidation or be dissolved, and make the space discrete or produce oxide film, which greatly reduced the corrosion resistance of oxide film. So, generally after anodic oxidation membrane must be closed to deal with, to improve its corrosion resistance.
(3) strong adsorption ability. Anodic oxidation of aluminium and aluminium alloy membrane is porous structure, has a strong adsorption capacity, so give hole filling all kinds of pigments, such as lubricants, resin can be further improve protection, insulation, wear resistance of aluminum products and decorative performance.
(4) it has good insulation performance. Aluminum and aluminum alloy anodic oxide film has no conductive properties of metal and is a good insulating material.
(5) the adiabatic thermal performance is strong. This is because the coefficient of thermal conductivity of anodic oxide film is much lower than the pure aluminium anodic oxide film can heat resistance around 1500 ℃, and pure aluminium can only 660 ℃. Above all, aluminum and aluminum alloy by chemical oxidation treatment, especially after anodic oxidation treatment, formed on the surface of oxide film has good protection features such as a decoration.