What is aluminum anodizing? what is anodized
An aluminum or aluminum alloy product is used as an anode, placed in an electrolyte solution for electrification treatment, and a process of forming an aluminum oxide film on the surface by electrolysis is called anodizing treatment of aluminum and aluminum alloy. After anodizing, the aluminum surface can form an oxide film of several micrometers - several hundred micrometers. Compared with the natural oxide film of aluminum alloy, its corrosion resistance, wear resistance and decorative property are obviously improved and improved.
The anodizing type of anodizing has long been widely used in industry. There are many ways to name different names, and there are several classification methods:
According to the current type, there are: direct current anodization, alternating current anodization, and production time that can shorten the required thickness, the film layer is thick and uniform, and the corrosion resistance is significantly improved by pulse current anodization.
According to the electrolyte, there are: sulfuric acid, oxalic acid, chromic acid, mixed acid and natural colored anodization with an organic sulfonic acid solution.
According to the properties of the film layer, there are anodization such as a common film, a hard film (thick film), a porcelain film, a bright modification layer, and a barrier layer for semiconductor action.
The application of direct current sulfuric acid anodic oxidation method is most common because it has anodizing treatment suitable for aluminum and most aluminum alloys; the film layer is thick, hard and wear resistant, and can obtain better corrosion resistance after sealing; The film is colorless and transparent, and has strong adsorption capacity and easy coloring; the processing voltage is low and the power consumption is small; the process does not have to change the voltage cycle, which is conducive to continuous production and practical operation automation; sulfuric acid has less harm to human body than chromic acid, and has a wide supply. , low price and other advantages.
The main purposes are: (1) to improve the wear resistance, corrosion resistance and weather resistance of the parts. (2) A transparent film formed by oxidation can be colored into various color films. (3) As a capacitor dielectric film. (4) Improve the adhesion to the organic coating. For the bottom layer of the coating. (5) For the bottom layer of electroplating and enamel. (6) Other uses under development, solar absorption plates, ultra-high hard films, dry lubricating films, catalytic films, nanowires, and magnetic alloys deposited in porous films as memory elements.