Characteristics and properties of aluminum substrates used in aluminum-plastic panels

The aluminum-plastic board is composed of two layers of aluminum on the top and bottom and a layer of plastic in the middle. Aluminum is the main substrate in aluminum-plastic panels. From the perspective of use, aluminum plays a supporting role for aluminum-plastic composite panels, accepts external impacts, and contacts the surrounding environment through the coating; from the manufacturing process, aluminum needs to go through After pre-treatment for painting, it needs to be compounded with plastic by adhesive. Therefore, the exterior wall aluminum-plastic board has strict requirements on the variety specifications, chemical composition, mechanical properties, dimensional deviation, and appearance quality of the aluminum substrate.

Aluminum is the fastest-growing metal material because it has many excellent properties, such as small density, high specific strength, good corrosion resistance, easy processing and beautiful surface, and can be colored by oxidation or decorated with a decorative coating. Therefore, it has been widely used in various fields of the national economy, especially in aviation, automobiles, electrical, light industry, transportation, construction and packaging. Aluminum and aluminum alloys are the most important materials in non-ferrous metals. They have many varieties and different performances. They involve a wide range of surfaces. It is not easy to fully understand and familiarize. In order to help the quality of aluminum substrates for aluminum-plastic composite panels First, on this basis, I will introduce the specific requirements of the aluminum substrate for aluminum-plastic plates on varieties, chemical compositions, mechanical properties, dimensional deviations, and appearance quality.

Characteristics and properties of aluminum substrates used in aluminum-plastic panels

Characteristics and properties of pure aluminum

(1) General characteristics of pure aluminum Aluminum was first discovered by the Danish scientific worker H. COersted in 1825 and has a history of more than 160 years. If the molten salt electrolysis method (Hall-Heroult method) for industrially refining aluminum was introduced in 1886, it would have been more than 100 years. For more than 100 years, aluminum and its alloys have been extremely widely used. In industry, agriculture, aviation, aerospace, defense industry, and even people's daily life, aluminum is widely used. The output of aluminum occupies the first place in nonferrous metals, second only to Steel production. The reason why aluminum is widely used, in addition to its rich reserves (approximately 8.2% of the crustal mass, is the most widely distributed metal element in the crust), smelting is relatively simple, more important is that aluminum has a series of excellent characteristics.

① Small density The density of pure aluminum is close to 2700kg/m3, which is about 35% of the density of iron.

② Although the strength of pure aluminum can be strengthened, it can be doubled by cold working. It can be alloyed by adding magnesium, zinc, copper, manganese, silicon, lithium, scandium and other elements, and then strengthened by heat treatment , Its specific strength is comparable to high-quality alloy steel.

③ Easy to process aluminum can be cast by any casting method. Aluminum has good plasticity, and can be rolled into thin sheets and foils, drawn into tubes and filaments, extruded into various civil profiles, and can be processed by turning, milling, hammering, and planing at the maximum speed that most machine tools can reach.

④ The surface of corrosion-resistant aluminum and its alloys is prone to form a dense and firm protective film. This protective film will only be destroyed under the violent action of halogen ions or alkali ions. Therefore, aluminum has good resistance to atmospheric (including industrial and marine atmosphere) corrosion and water corrosion. It can resist most acids Corrosion with organic substances, using corrosion inhibitors, can withstand weak liquid corrosion; using protective measures can improve the corrosion resistance of aluminum alloys.

⑤ No low temperature brittleness

Aluminum is below 0°C. As the temperature decreases, the strength and plasticity will not only decrease but increase.

⑥ Good electrical and thermal conductivity

Aluminum's electrical and thermal conductivity is second only to silver, copper and gold. At room temperature, the equivalent volume conductivity of electrical aluminum can be up to 62 MIACS. If calculated according to the electrical conductivity per unit mass, its electrical conductivity is double that of copper.

⑦ Sound absorption

It is good for interior decoration and can also be made into damping alloy.

⑧Nuclear radiation resistance

For high-energy neutrons, aluminum has the same degree of neutron absorption cross section as other metals. For low-energy neutrons, its absorption cross section is small, second only to metals such as beryllium, magnesium, and zirconium. The biggest advantage of aluminum's resistance to nuclear radiation is that the radiation energy decays quickly,

⑨Beautiful

Aluminum and its alloys have strong reflection ability, and the surface is silver-white gloss. After machining, it can achieve high brightness and the surface is very smooth. If it is anodized and colored, it can not only improve the corrosion resistance, but also obtain colorful and bright products.