Temperature-supported forming of automobile related magnesium components

Lightweight design in passenger cars is gaining more and more importance. Independent from conventionally or electrically drive train concepts, weight reduction is one of the most rated defining variables for fuel or energy consumption, thus affecting the range of the vehicle. Overall, the potential for using steel in lightweight bodywork construction has attained a high level of development with the result that the potential for further optimisation is increasingly diminishing. As a consequence, alternative lightweight construction materials are set to become more important in the future. Another focus is related to costs and availability of basic materials. It is well known from the aircraft industry that CFRP structures have a very high level of lightweight potential - however, the available manufacturing technologies and production rates are not feasible for the production of larger series applied in the automotive industry. Compared to the beneficial application potential regarding bending and distortion of steel- and Aluminium compared to Magnesium blanks, this material becomes more and more interesting for automobile applications. Beside challenges like corrosion and recycling, mainly an appropriate forming technology lies in the focus of investigations. Based on the crystalline structure, the forming conditions of Magnesium blanks at room temperature are not useful for complex geometries in car applications. When introducing temperature as additional process parameter, the forming limits of Magnesium sheets can be increased up to 250 - 400 %. Due to this phenomenon the focus of investigation was related to the characterisation of material properties depending on temperature, the thermo-mechanical forming simulation for process and tool design and the practical realisation of complex, car-related part geometries as well as requirements for forming tools and additional devices. In the following article we will present the results of studies into the forming of magnesium sheets (AZ31) including tailored blanks, achieved within a growth cell (TeMaK and TeMaK+).