The strongest aluminium alloys (2xxx, 6xxx and 7xxx) are produced by precipitation (or age) hardening.

In the first section, you can learn how a fine dispersion of precipitates can be formed by appropriate heat treatment.

The second section shows how these precipitates strengthen the alloy by inhibiting dislocation mobility.

Before starting, it is important that you have a basic understanding of binary phase diagrams. You should also be familiar with the following terms: phase, equilibrium, Gibbs' free energy, solid solution.