What is the difference between anodized aluminum plate and ordinary aluminum plate?

Different production processes

Ordinary alumina plate:

Generally, a thin aluminum oxide film is naturally formed by rolling aluminum plates. This kind of oxide film is relatively thin, which is usually generated by natural oxidation reaction between aluminum and oxygen in the air during aluminum plate processing, and the thickness is between several nanometers and dozens of nanometers. For example, an oxide film of about 5-10nm will naturally form on the surface of an aluminum plate placed in a general environment, which has a certain protective effect on the aluminum plate, but it is relatively weak.

Anodized alumina plate:

By electrochemical oxidation, aluminum plate is used as anode, and direct current is applied in a specific electrolyte (such as sulfuric acid and oxalic acid) to form a thick and compact aluminum oxide film on the surface of aluminum plate. This process is carried out under manual control, and the thickness of oxide film can be adjusted according to actual needs, generally between 5-20 μ m. For example, in the anodic aluminum oxide plate for architectural decoration, the thickness of the oxide film may reach 10-15μm, and the oxide film with this thickness has better performance.

Different performance characteristics

Corrosion resistance:

Ordinary alumina board: Because of its thin oxide film, its corrosion resistance is relatively weak in some corrosive environments. For example, in a humid environment containing a small amount of acidic or alkaline substances, this thin oxide film may be gradually corroded and destroyed, resulting in the exposure of aluminum inside the aluminum plate, and further corrosion will occur.

Anodized aluminum oxide plate: Its thick oxide film structure is compact and has better corrosion resistance. It can resist the corrosion of many chemicals. For example, in areas with frequent acid rain, when the anodic aluminum oxide plate is used as a building curtain wall material, it can maintain the surface integrity for a long time and effectively prevent the aluminum plate from being corroded.

Hardness and wear resistance:

Ordinary alumina plate: the hardness is relatively low and the wear resistance is limited. If the surface is rubbed or scratched, it is easy to leave traces. For example, in daily use, the surface of furniture made of ordinary alumina board is easy to be scratched if it is often in contact with hard objects, which affects the appearance.

Anodized aluminum plate: the hardness of the oxide film is relatively high. After anodic oxidation, the hardness of aluminum plate can be significantly improved, usually reaching HV300-500 (Vickers hardness). This makes the anodized aluminum plate have good wear resistance, and can withstand a certain degree of friction and scraping without being easily damaged. For example, anodic aluminum oxide plates used in industrial floors or mechanical parts can maintain a good surface condition even in the environment of high-flow people walking or machine running.

Color and appearance:

Ordinary aluminum oxide plate: the color mainly depends on the material of aluminum plate itself and the color after natural oxidation, generally silvery white or grayish white, and the color is relatively simple. The appearance is relatively monotonous and the gloss is limited.

Anodized aluminum plate: In the process of anodic oxidation, different colorants can be added to make the surface of aluminum plate show various colors, such as black, red and gold. Moreover, its surface can have high gloss, such as mirror effect, or various appearance effects such as frosting and wire drawing can be obtained through special treatment, which is very decorative.

Different application fields

Ordinary alumina plate:

It is mainly used in some fields that do not require high performance of aluminum plates. For example, in some simple industrial packaging, non-exposed parts of ordinary buildings, etc., it is used as a basic metal material to exert its basic metal characteristics, such as certain strength and toughness.

Anodized alumina plate:

Because of its good performance and rich appearance, it is widely used in architectural decoration (such as curtain wall, interior decoration), electronics industry (such as electronic component shell), automobile industry (such as automobile interior, wheel hub), aerospace (such as aircraft interior) and other fields, and is used in occasions where high performance and beautiful appearance are needed.