Manufacturing of long products made of innovative lightweight materials

The processing of innovative lightweight materials to sheet metal components and assemblies with globally or locally defined properties is the object of joint research at the Fraunhofer Institute for Machine Tools IWU and Forming Technology and the Professorship Forming and Joining UFF of Technische Universität Chemnitz. It takes a load-dependent design of components and assemblies e.g. based on the composition of different construction materials or a targeted setting of component areas with specified characteristics to fully exploit the lightweight potential when substituting conventionally used materials. Different process chains for the manufacturing of roll formed long products made of magnesium alloys and high strength steels with locally defined properties will be presented in this paper. Depending on the kind of material to be formed and the desired product characteristics, different temperature managements are needed for capable processes. Due to limited formability at room temperature, Magnesium alloys require a heating of the forming zones above 200 to 225 °C throughout the bending process in order to activate additional gliding planes and to avoid any failures in the radii. The realization of local hardening effects requires at least one process-integrated heat treatment when roll forming Manganese-boron steels. For both processes it is imperative to realize a heating and cooling down or quenching appropriate for the manufacturing of long products with the required quality. Additionally proper line speeds that allow a continuously operated economical production have to be considered. Research results including design, FEA, realization and experimentation of the mentioned process chains and strategies will be described in detail.