Artificial ageing (Topic: 10047)

By heating the solution heat-treated material to a temperature above room temperature and holding it there the precipitation accelerates and the strength is further increased compared to natural ageing (accompanied by a corresponding drop in ductility). This is called "artificial ageing", "age hardening" or just "ageing" and is carried out at temperatures up to 200°C (for 6000-alloys normally between 160 and 200°C).

During ageing at a specific temperature the mechanical strength increases up to a maximum level at a specific ageing time. At this maximum point the hardening precipitates are at a state where further ageing will make them loose coherency with the aluminium lattice and grow coarse. This is called overageing and will result in a drop in strength.