Due to the properties of aluminum and the associated lightweight potential, it is increasingly used in the automotive sector. High strength alloys are often used for safety-relevant components that protect the passenger compartment in the event of a crash. Ensuring high strength with sufficient ductility in the application at the same time is a major challenge. In addition, the high degrees of forming involved in the manufacture of these structural components, such as by hot-extrusion, must be taken into account. In order to meet this requirement, it is essential to understand the precipitation sequences of hardenable Al alloys.

Depending on the alloy system in use, natural aging can have a positive or negative effect on the mechanical properties. Furthermore, different minor and major elements play a decisive role.

In this contribution, the role of different natural ageing times and alloy compositions on clustering and precipitation-behaviour is investigated. In this context, different states like naturally aged, stabilized, peak aged and over aged are analysed, using classical methods like hardness and conductivity measurements. To gain a deeper microstructural insight, detailed investigations using TEM and APT-methods are carried out.