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Every morning when we wake up from our sleep and start a day's life and work, there is always something like old friends who accompany us all day, that is aluminum, which has been integrated into our life, and its shadow is everywhere.

Aluminum is the most abundant metal element in the earth's crust. The aluminum alloy made of aluminum as the main material and other metals has many excellent properties, such as lightness, environmental protection, corrosion resistance, etc. It provides us with various conveniences. Aluminum, known as green metal, has good recycling characteristics. Up to now, about 70% of aluminum produced 100 years ago is still serving mankind.

APPLICATION

From high-speed rail cars to ships, from military to civilian use, the use of aluminum alloys is increasing. Every 1kg reduction in the weight of spacecraft entering space orbit will save more than 100000 yuan in launch costs.

Energy saving and weight reduction are calculated in grams in the aerospace field. The aerospace field has become an important application market of aluminum alloy materials. Automotive engines, wheel hubs, body, high-speed rail body, mechanical equipment and electrical equipment, as well as daily necessities, are all made of aluminum alloy to meet the requirements of lightweight.

HISTORY

In ancient times, humans began to use aluminum-containing clay to make pottery. However, due to its weak oxidation performance, it is difficult to extract it, so its reserves on the earth are more than other metals, but its use is significantly later than copper, iron and other metals.

In 1825, German chemists refined gray metal aluminum with low purity.

In 1854, French chemists successfully made metal aluminum ingots using sodium as a reducing agent. After that, aluminum became an expensive material. Products made of aluminum could only be enjoyed by emperors and nobles.

In 1884, other metals were added to aluminum to make aluminum alloy materials, which were first used in construction.

In 1908, American company invented electrical aluminum alloy, which is characterized by high hardness and high copper content, and is applied to high-voltage transmission lines.

Later, it successively invented cast aluminum alloy and high-strength aluminum alloy, and its application scope is also expanding.

Aluminum alloy is the general name of alloy with aluminum as the main material. The main alloy elements include copper, silicon, magnesium, zinc, etc. Aluminum alloy has the advantages of corrosion resistance, easy processing, high strength, low density, etc. Aluminum alloy has corrosion resistance, which is impossible for many metals. Because there is a hard film on the surface of aluminum alloy, this film covers the surface of aluminum alloy and insulates the aluminum alloy from oxygen. With the extension of time, this film will continue to thicken. If this film is damaged, it will grow a protective film again, making its aluminum products have good corrosion resistance. Of course, it also needs the surface treatment in the later stage to make the aluminum alloy more corrosion resistant.

Many people think that aluminum will not oxidize. In fact, there is no absolutely non-oxidizable metal in the world, but the conditions and degree are different. If the surface protective film of aluminum alloy is damaged, it will also oxidize.

The disadvantage of aluminum alloy is also obvious, that is, it is too brittle. Now scientists have developed a new type of aluminum alloy material. The disadvantage of aluminum alloy is being changed. By introducing a "fault" in the crystal structure of the metal, the strength of the material can be greatly improved. In addition to making the strength of the new aluminum alloy material similar to that of stainless steel, this feature can also be used for corrosion resistant coating.

From the microscopic level, metal is composed of crystal atoms stacked repeatedly layer by layer. When a layer is missing, it will cause collapse and fracture of the stack. Interestingly, these stacked faults can make the strength of the material higher. This feature is introduced into the new aluminum material, which improves its thermal stability while increasing its strength and ductility, The new product is expected to be applied in the anti-corrosion coating of electronic equipment and vehicles.

Source: Manufacturing principle