Sheet-Bulk Forming: From fundamentals and formability limits to tailored laser heat treatment

Sheet-bulk forming combines the plane stress conditions of sheet forming with the three-dimensional stress states of bulk forming. It produces net-shape sheet parts with local functional features, such as teeth, ribs, bosses and flanges, placed outside the plane of the blank. Integrating these features into a single part reduces the number of components, shortens process chains, and supports lightweight design in the automotive, railway, and defense sectors. The seminar introduces the classification of sheet-bulk forming processes and a process-independent view based on three fundamental material flows: thickening, local thickening and injection. Applications are presented first in sheets, using a flexible laboratory demonstrator, and then in thin-walled tubes, through boss forming and injection forging of flanges. Formability is discussed through fracture in tension, in-plane shear, and out-of-plane shear. Finally, joint work with Politecnico di Bari shows how tailored laser heat treatment of AW6082-T6 sheets reduces forming forces, prevents fracture, and widens the process window. The seminar closes with conclusions and future trends.