In terms of prevalence in nature, the first place among metals is occupied by aluminum (Al): in the earth's crust it is 60 percent more than iron, and in terms of production and scale of use, it is second only to ferrous metals. Widespread use is due to the most important properties of aluminum - low density (2700 kg / m3), high electrical and thermal conductivity, good corrosion resistance in the atmosphere and a number of aggressive media.
Aluminum properties and applications:
- high reflectivity of aluminum is used for the production of powerful reflectors, mirrors, large television screens;
- high ductility of aluminum ensures good workability of aluminum by pressure both in cold and hot conditions. Aluminum and its alloys do not lose plasticity at low temperatures, therefore, tanks for cryogenic liquids, heat exchangers for helium liquefaction, etc. are made of them;
- high electrical conductivity of aluminum has led to the widespread use of aluminum in electrical engineering (instead of more expensive and heavy copper) for the manufacture of wires, cables, switchgear buses, capacitors, etc .;
- high thermal conductivity of aluminum is used for various heat exchangers, in industrial and domestic refrigerators;
- aluminum is resistant to corrosion in the atmosphere due to the formation of a dense oxide film on its surface, it does not corrode in fresh water, has high corrosion resistance in uncontaminated seawater, concentrated nitric acid and some organic acids (acetic, citric, butyric, etc.);
- in the aviation industry, pure aluminum is used for oil and gas pipelines, in the form of foil for honeycomb structures;
- in the latter days, the use of aluminum in construction has increased (house facades, window frames, handrails, handles, etc.);
- aluminum is also used in nuclear engineering, pyrotechnics, aluminothermy, to protect the surfaces of metallic materials from corrosion, etc.
- The bulk of aluminum is spent on the production of aluminum alloys, which, due to their low density and sufficient strength, are widely used in mechanical engineering (especially aircraft construction) and construction.