Aluminium is used excessively in the modern world, and the uses of the metal are extremely diverse due to its many unusual combinations of properties. No other metallic element can be used in so many ways across such a variety of domains, like in the home, in transport, on land, sea and in air, and in industry and commerce. Aluminium's uses are not always as obvious as they may seem, with sizeable proportions of manufactured aluminium and aluminium oxide going into other separate processes, like the manufacture of glass, rather than towards the common consumer products that we most readily associate Aluminium with.
PackagingOne of the most common end uses of aluminium is packaging, including drinks cans, foil wrappings, bottle tops and foil containers. Each of these relies on aluminium to provide a way of containing the food cleanly, and to protect it from changes in the local environment outside the packaging. Aluminium is still used in a very big way in the food packaging industry despite recent health worries linking aluminium to Alzheimer's disease. Aluminium's natural resistance to corrosion aids it in its role in packaging (and many other areas), as unlike in iron, aluminium oxide forms a protective and not destructive layer. Aluminium is also completely impermeable, (even when rolled into extremely thin foil), and also doesn't let the aroma or taste out of food packaging, the metal is non-toxic and aromaless itself too, making it perfect for packaging.
Used in Aeroplanes.Aluminium's unbeatable strength to weight ratio1 gives it many uses in the transport industry. Transport is all about moving things around and to do so a force is always required. As force = mass x acceleration (Newton's Second Law of Motion), less force is needed to move a lighter object to a certain acceleration than is needed to get a heavier object to the same acceleration. As aluminium is so lightweight this means that less energy needs to be used to move a vehicle made with aluminium than one made from a heavier metal, say steel. Although aluminium isn't the strongest of metals its alloys use other elements to pin dislocations in its structure to increase its strength. With trains, boats and cars aluminium is useful for this lightweight property (which gives fuel efficiency) but not essential, in planes however maintaining a relatively low weight is vital (in order to level the ground), and aluminium allows planes to have to this. In modern planes aluminium makes up 80% of their (unladen) weight, and a normal Boeing 747 contains about 75 000 kg of the metal. Its corrosion resistance is an advantage in transport (as well as packaging) as it makes painting planes unnecessary saving some hundreds of kilograms of further weight.
Aluminium in powerlines.Weight is also important in aluminium's electrical uses, where it's low density2 makes it the first choice for long distance powerlines despite having just 63% of the electrical conductivity of (much denser) copper. In fact 1 kg of aluminium conducts almost twice as much electricity as 1 Kg of copper. Since 1945 aluminium has been used in high voltage electrical transmission, in place of copper as it is the most cost efficient power line material. With copper many heavy, and expensive support structures needed to be used, yet using aluminium fewer lighter and cheaper supports have to be used. This saves huge amount of money, despite a wastage in electricity due to lower conductivity. Aluminium is also more ductile than copper, so it is easier to draw it into wires to produce these power lines, its corrosion resistance completes aluminium's profile as the perfect choice for long-distance electricity distribution. Aluminium has other electrical applications too including TV aerials, satellite dishes, and being the standard base for bulbs.
Buildings made with aluminium are virtually maintenance free due to the strength of aluminium's corrosion resistance. Due to this and its light weight it is used in cladding, windows, skylights, gutters, door frames, and roofing. Insulated aluminium cladding is also very thermally efficient, keeping homes warm in winter, and cool in summer. One layer of insulated aluminium cladding is as effective as four inches of brick or ten of stone. Aluminium can also be painted and used with other material to achieve a particular effect on the appearance of a building. The metal is extremely versatile and it can be curved, tapered, welded, bonded and cut to any shape to be used for a certain job.
Ideal in construction.
Aluminium also has further end uses in products used more readily around the home. Like all the other uses they relate specifically back to the properties of the metal. The material is used to make saucepans, kitchen utensils, golf clubs, tennis bats, indoor and outdoor furniture, fridges, and toasters.
Summary: Aluminium has a huge number of uses. These range from all sorts of packaging, through to aeroplanes, cars and train carriages. Aluminium is also vital in powerlines, the building and construction industry and commonplace household objects. The key features that lend aluminium to these uses are corrosion resistance, low density, ductility, electrical conductivity and strength in alloys