Uses of aluminium

Uses of aluminium

Aluminium is usually alloyed with other elements such as silicon, copper or magnesium. Pure aluminium isn't very strong, and alloying it adds to it strength.

Aluminium is especially useful because it

has a low density;

is strong when alloyed;

is a good conductor of electricity;

has a good appearance;

resists corrosion because of the strong thin layer of aluminium oxide on its surface. This layer can be strengthened further by anodising the aluminium.

Anodising essentially involves etching the aluminium with sodium hydroxide solution to remove the existing oxide layer, and then making the aluminium article the anode in an electrolysis of dilute sulphuric acid. The oxygen given of at the anode reacts with the aluminium surface, to build up a film of oxide up to about 0.02 mm thick.

As well as increasing the corrosion resistance of the aluminium, this film is porous at this stage and will also take up dyes. (It is further treated to make it completely non-porous afterwards.) That means that you can make aluminium articles with the colour built into the surface.

Some uses include:

aluminium is used for	because
aircraft	light, strong, resists corrosion
other transport such as ships' superstructures, container vehicle bodies, tube trains (metro trains)	light, strong, resists corrosion
overhead power cables (with a steel core to strengthen them)	light, resists corrosion, good conductor of electricity
saucepans	light, resists corrosion, good appearance, good conductor of heat