Is anodic hardening the same as anodizing? Why is the anodized material aluminum or aluminum alloy?

The surface hardness of aluminum alloy anodizing is up to 250 500 kg square millimeter, because the high hardness determines the wear resistance of the oxide film is very good.

Aluminum alloy is anodized and colored, with high hardness, wear resistance, corrosion resistance and good electrical insulation, and can also be electroplated, electrophoresis, sprayed and so on to further improve the decoration and protection of aluminum through chemical pretreatment.

The hardness is generally around HV300, and the hard oxide film (low-temperature oxide film) can reach about HV500 if I remember correctly.

The pore size of the oxide film is between 100nm and 200nm, the thickness of the oxide film is about 10 microns, the porosity is about 20%, and the pore spacing is between 300 and 500nm. The cross-sectional view of the oxide film shows that the pores of the oxide film are basically tubular structures, and the dissolution reaction of the oxide film basically occurs at the bottom of the pores.

The pore size of the general sulfuric acid DC anodizing film is about 20nm, if it is a 12 micron oxide film, it is a deep thin tubular structure, assuming that this is a well with a diameter of 1m, then its well depth will be 600m deep.

Film thickness is a very important performance indicator of anodized products, and its value directly affects the corrosion resistance, wear resistance, insulation and chemical coloring ability of the film layer. In the conventional anodizing process, the film thickens over time.

After reaching the maximum thickness, it gradually thins with the extension of treatment time, and some alloys such as AI-MG and AI-MG-ZN alloys are particularly obvious. Therefore, the time of oxidation is generally controlled within the maximum film thickness time.

After aluminum anodizing, the hardness of aluminum itself has not changed, and it is only the oxide film outside the aluminum that hardens, and the hardness is generally about HV300, and the hard oxide film (low-temperature oxide film) can reach about HV500 if I remember correctly, which is higher than ordinary stainless steel. If you are satisfied, you will be divided.

HV650-700 can be achieved with a freezer for low-temperature oxide film

Anodizing. anodic oxidation), electrochemical oxidation of metals or alloys. aluminum and its alloys in the corresponding electrolyte.

and the process of forming an oxide film on aluminum products (anodes) under specific process conditions due to the action of applied current. Anodizing usually refers to sulfuric acid anodizing, if not specifically specified.

In order to overcome the defects of aluminum alloy surface hardness, wear resistance, etc., expand the scope of application, prolong the service life, surface treatment.

Technology has become an indispensable part of the use of aluminum alloys, and anodizing technology is the most widely used and successful.

In order to overcome the defects of aluminum alloy surface hardness and wear resistance, expand the application range and prolong the service life, surface treatment technology has become an indispensable part of the use of aluminum alloy. Metal oxide films change the surface state and properties, such as surface coloring, improving corrosion resistance, enhancing wear resistance and hardness, protecting metal surfaces, etc.

Generally speaking, the anode is made of aluminum or aluminum alloy as the anode, and the cathode is selected from the lead plate, and the aluminum and lead plate are placed together in an aqueous solution, which contains sulfuric acid, oxalic acid, chromic acid, etc., for electrolysis, so that the surface of the aluminum and lead plate forms an oxide film. Anodizing usually refers to sulfuric acid anodizing, if not specifically specified.

Definition: A material protection technology in which an anode current is applied to the surface of a metal material in an electrolyte solution to form an oxide film.

Oxidation environment: generally carried out in an acidic electrolyte.

Oxidation process: The anion of oxygen reacts with aluminum to produce an oxide film. This kind of film is not fine enough when it is initially formed, although there is a certain resistance silver with silver, but the negative oxygen ions in the electrolyte can still reach the surface of the aluminum and continue to form an oxide film.

As the thickness of the film increases, so does the resistance, resulting in a smaller electrolytic current. At this time, the outer oxide film in contact with the electrolyte is chemically dissolved. When the rate at which oxides form on the surface of aluminum gradually equilibrates with the rate at which chemical dissolution, the oxide film can reach a maximum thickness.

Line years. Advantages of aluminum alloy anodizing: the outer layer of the anodized film of aluminum is porous, which is easy to adsorb dyes and colored substances, so it can be dyed and improve its decoration. After the oxide film is sealed with hot water, high-temperature water vapor or nickel salt, its corrosion resistance and wear resistance can be further improved.

1. Anodizing, electrochemical oxidation of metals or alloys. The process of forming an oxide film on aluminum products due to the action of impressed current under the corresponding electrolyte and specific process conditions. Anodizing usually refers to sulfuric acid anodizing, if not specifically specified.

2. In order to overcome the defects of aluminum alloy surface hardness and wear resistance, expand the application range and prolong the service life, surface treatment technology has become an indispensable part of the use of aluminum alloy, and anodizing technology is currently the most widely used and most successful.