Manufacturing of tailored aluminum parts by controlling the local cooling rates in a combined forming, quenching and hardening process (Tailor Quenched Forming)

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A common method for increasing passenger safety in vehicles is the use of high strength materials for structural safety-relevant parts. Due to the targeted adjustment of the mechanical properties, tailored components can be manufactured with locally adapted component strengths. In case of a crash, they have the ability to absorb or transfer the occurring energy to other regions of the vehicle. It is relevant that these components combine high-strength as well as ductile regions. Until now these components are only produced by modified press hardening operations of steel components. In association with the light-weight concept, a new opportunity to realize tailored components is the use of adapted, high-strength, hardenable aluminum components. During the forming process, the properties of previously solution-annealed components can be adjusted by simultaneous quenching and forming operations. The key influencing factor in quenching and forming operations is the cooling rate. In future, it will be possible to produce property-adapted structural components using high-strength aluminum alloys with the help of different local tool temperatures. Thermally coupled material models are necessary for the simulation of this forming process. Aim of this project is therefore at first the determination of the microstructural behavior of high-strength aluminum alloys as a function of cooling rate as well as mechanical stress states. The determined material properties will then transferred into a thermomechanically coupled material model and a precipitation simulation will be derived. This enables the transfer of the simultaneous forming and quenching operation into a FEM simulation. The influencing variables of the heat transfer between tool and component are investigated by experiments. Furthermore, the possibility of tool-internal hardening in comparison to conventional hardening in a furnace is investigated. The results are verified using a simplified demonstrator geometry.