Ageing of aluminium is carried out at room temperature (cold ageing) or at elevated temperature (artificial ageing). The alloy atoms which, after dissolution and cooling in supersaturated solution in the material, form by diffusion small precipitates that increase the strength of the material.

Recommended times and temperatures must be monitored closely for best results. Generally, if the ageing temperature is increased, the time may be reduced, but the strength achieved will be lower.

Ref. Gränges Alumium, Aluminiumlära