Application Of Aluminum

  The use of a substance depends largely on its properties. Aluminum has a wide range of applications because of its excellent properties.

  (1) The density of aluminum is very small, only 2.7 g / cm3. Although it is relatively soft, it can be made into various aluminum alloys, such as hard aluminum, super hard aluminum, antirust aluminum, cast aluminum, etc. These aluminum alloys are widely used in aircraft, automobiles, trains, ships and other manufacturing industries. In addition, space rockets, space shuttles and satellites also use a large amount of aluminum and its alloys. For example, a supersonic aircraft is composed of about 70% aluminum and its alloy. Aluminum is also widely used in ship construction, and the aluminum consumption of a large passenger ship often reaches several thousand tons.

  (2) The conductivity of aluminum is second only to silver and copper. Although its conductivity is only 2 / 3 of that of copper, its density is only 1 / 3 of that of copper. Therefore, the quality of aluminum wire is only half of that of copper wire when the same amount of electricity is transmitted. The oxide film on the surface of aluminum not only has the ability of corrosion resistance, but also has a certain degree of insulation. Therefore, aluminum is widely used in the electrical manufacturing industry, wire and cable industry and radio industry.

  (3) Aluminum is a good conductor of heat. Its thermal conductivity is three times greater than that of iron. Aluminum can be used to manufacture various heat exchangers, heat dissipation materials and cookers in industry.

  (4) Aluminum has good ductility (its ductility is second only to gold and silver), and can be made into aluminum foil thinner than 0.01 mm at 100 ℃ ~ 150 ℃. These aluminum foils are widely used for packaging cigarettes, sweets, etc., and can also be made into aluminum wires and strips, and can roll various aluminum products.

  (5) Because of the dense oxide protective film on the surface of aluminum, it is not easy to be corroded. It is often used to manufacture chemical reactors, medical devices, refrigeration devices, oil refining devices, oil and natural gas pipelines, etc.

  (6) Aluminum powder has silver white luster (generally, the color of metal in powder form is mostly black). It is often used as coating, commonly known as silver powder and silver paint, to protect iron products from corrosion and beautiful.

  (7) The combustion of aluminum in oxygen can release a large amount of heat and dazzling light. It is often used to produce explosive mixtures, such as ammonium aluminum explosives (made of ammonium nitrate, charcoal powder, aluminum powder, soot and other combustible organic substances), combustion mixtures (such as bombs and shells made of thermite can be used to attack targets or tanks and cannons that are difficult to ignite), and lighting mixtures (such as barium nitrate 68%, aluminum powder 28%, shellac 4%).

  (8) Thermite is often used to melt refractory metals and weld rails. Aluminum is also used as a deoxidizer in the steelmaking process. Aluminum powder, graphite, titanium dioxide (or oxides of other high melting point metals) are uniformly mixed in a certain ratio, coated on the metal, and calcined at high temperature to make high-temperature resistant cermet. It has important applications in rocket and missile technology.

  (9) Aluminum plate also has good light reflection performance. The reflected ultraviolet ray is stronger than silver. The purer aluminum is, the better its reflection ability is. Therefore, it is often used to manufacture high-quality mirrors, such as solar oven mirrors.

  (10) Aluminum has sound absorption performance and sound effect, so the ceiling of broadcasting room and modern large-scale building also uses aluminum.