Aluminium is highly corrosion resistant so it is possible to remelt and reuse it an infinite number of times. The recycling process requires only 5% of the energy needed to make the same amount of primary aluminium. From an environmental friendly point of view this is one of the major benefits aluminium offers. Statistically more than 70 percent of all aluminium ever produced is still in use,
After iron, aluminium is now the second most widely used metal in the world. In the Earth's crust, aluminium is the most abundant (8,3% by mass) metallic element. Although aluminium is a common and widespread element, the pure form of aluminium does not naturally occur in nature. Nearly all metallic aluminium is produced from the ore bauxite. Large deposits of bauxite occur in Australia, Brazil and Guinea.
Low density and therefore low weight, high strength, superior malleability, easy machining, excellent corrosion resistance and good thermal and electrical conductivity are amongst aluminium’s most important properties. Especially aluminiums flexibility its strength and light weight make it so attractive in many different applications for household goods (packaging and conservation) and of course for the processing industry and construction industry. Its lightweight does not affect its strength. Commonly aluminiums alloys have a tensile strength of between 70 and 700 MPa. It does not become brittle at low temperatures unlike most other steel grades. At higher temperatures its strength decreases continuously. At temperatures above 100° C the weakening must be taken into account.
Aluminium has a relatively large coefficient of linear expansion compared with other metals. It is easily machined by the most common machining methods like: milling, drilling, cutting, bending and punching. Because of its low density the energy input during machining is low. It is easily processed in cold and hot conditions. Aluminium melts at 660° C without releasing any gases.
Furthermore aluminium is an excellent conductor of heat and electricity. An aluminium conductor weighs approximately half as much as a copper conductor having the same conductivity. And aluminium is a great reflector it reflects heat and light. It is ideal as reflector for light fittings.
With the oxygen in the air it reacts to form an extremely thin layer of oxide. This layer provide excellent corrosion protection and is self-repairing if damaged. This makes aluminium extremely durable in neutral and slightly acid environments.