The basis of aluminum sacrificial anode cathodic oxidation treatment is described

Aluminum with anodized alumina film is sometimes more resistant to corrosion than chromate treated aluminum.

In electrolysis, anion of oxygen interacts with aluminum to produce an oxide film.

The basis of anodic oxidation treatment of aluminum is described

. The power supply can be DC, AC or ALTERNATING DC. The voltage is between 5 and 25 volts, and the temperature is below 25℃. The anodic oxide film produced by various electrolytes has different colors, some of which are overall colored, and most of which are used in the construction industry. Some can be colored with dyes or by means of hydrolysis and compound decomposition, so that the pigment formed is deposited in the hollow section of the hexangular column to increase the aesthetic feeling. The initial formation of this film is not fine enough, there is a certain resistance, so that the negative oxygen ions in the electrolyte can still reach the surface of aluminum oxide film inheritance.

Finally, we need to seal and dry. The structure of anodic oxide film of aluminum is different from other conversion films. The compact layer near the base metal is 0.01 ~ 0.1 micron, and on it is a honeycomb layer composed of many hollow hexagonal cylinders, with total thickness ranging from 2 ~ 100 micron. One of the most commonly used is the sulfuric acid group. A part with very low friction coefficient can be obtained by filling polytetrafluoroethylene in the floating hexagonal column of common anodic alumina layer. Anodic oxidation of aluminum has a variety of electrolytes, but basically sulfuric acid, chromic acid, glyoxic acid or boric acid as the main group of preparation. In addition to widely used in the construction industry and daily hardware products, this aluminum is also used in aircraft, automobiles, civil ships. With the increase of the film thickness, the resistance becomes larger, the electrolytic current becomes smaller, and the outer oxide film in contact with the electrolyte is chemically dissolved at the same time. When the oxide formation rate on the aluminum surface gradually balances with the chemical dissolution rate, the oxide film can reach the maximum thickness under this electrolytic parameter. The use of low temperature, weak dissolution of the electrolyte and high voltage (100 ~ 150 VOLTS), can be formed for engineering hard anodic oxide film, for mechanical parts and hydraulic components in contact with fibers, paper and rubber.

A material protection technique in which an oxide film is produced on the surface of an aluminum anode by electrolysis in an acid electrolyte.