Why are alloys typically stronger than pure metals?

Alloys are typically stronger than pure metals because they have a more complex structure that resists deformation.

Pure metals consist of identical atoms arranged in a regular, repeating pattern. This structure allows layers of atoms to slide over each other easily, which can lead to deformation under stress. In contrast, alloys are made up of different types of atoms. The different sizes and properties of these atoms disrupt the regular pattern found in pure metals, making it harder for layers of atoms to slide over each other. This makes alloys more resistant to deformation, and therefore stronger.

The process of alloying involves mixing a primary metal with one or more other elements. These additional elements can be other metals, or non-metals such as carbon. The atoms of these additional elements fit into the gaps between the atoms of the primary metal, or replace some of the primary metal atoms. This disrupts the regular structure and creates a more complex arrangement of atoms.

For example, steel is an alloy of iron and carbon. The carbon atoms are much smaller than the iron atoms and fit into the gaps between the iron atoms. This disrupts the regular pattern of the iron atoms and makes it harder for them to slide over each other. As a result, steel is much stronger than pure iron.

In addition to increasing strength, alloying can also improve other properties of metals. For example, it can increase resistance to corrosion, improve heat resistance, or change the colour of the metal. This makes alloys very versatile and useful in a wide range of applications.