Reduction of anisotropic material properties during extrusion through additively manufactured extrusion dies

• Applicants: Professor Dr.-Ing. Noomane Ben Khalifa; Dr. Jan Bohlen
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 455039650

The proposed project deals with the development of the anisotropic mechanical behavior of metallic profiles during the extrusion of profiles and with concepts to influence and balance this behavior. The development of anisotropic properties during extrusion is revealed for different types of materials, especially aluminium and magnesium. However, it can vary in quantity depending on the alloys and geometries. A new approach is suggested to control the material flow in the extrusion die in a way that the anisotropy of the mechanical properties is specifically and measurably influenced and reduced. The possibility of controlling the material flow is realized by a novel design of extrusion dies and its production using additive manufacturing technology. Then geometries can be represented which cannot be achieved using conventional manufacturing processes.The mechanical properties of the materials are specifically influenced by the directional material flow and the associated microstructure development. On the crystallographic level, this deformation produces distinct textures, therefore causing anisotropic mechanical properties of the extruded profile due to the directionality of activated deformation mechanisms. The targeted adaptation of the material flow in the die and the resulting change in the stress and strain states during forming can thus be described and controlled. This makes it possible to define design guidelines for the microstructure development required for the targeted reduction of the anisotropic mechanical behavior of the extruded profiles.

• DFG Programme: Research Grants