Converting pure metals into alloys often increases the strength of the product. For example, brass is an alloy of copper and zinc. It is stronger than copper or zinc alone:
|Metal||Tensile strength (MPa)|
Explaining alloy strength
Solid metals have a regular lattice structure. When a force is applied to a metal, layers of atoms can move past each other. The more difficult it is for the layers to move, the more force is needed and the stronger the metal.
Copper and zinc atoms are different sizes. This distorts the regular lattice structure in brass, so layers of atoms cannot slide over each other so easily. This makes brass stronger than copper or zinc alone.
Explain why stainless steel is used to make washing machines and dishwashers.
Washing machines and dishwashers contain water. This would cause other steels to rust, but stainless steel does not rust.
The table shows some other alloys and their typical uses.
|Brass||Copper and zinc||Coins, musical instruments|
|Bronze||Copper and tin||Propellers for ships, bells|
|Duralumin||Aluminium and copper||Aircraft parts|
|Solder||Tin and lead||Joining copper pipes and electrical components|