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

拟议的项目涉及型材挤压过程中金属型材各向异性力学行为的发展，以及影响和平衡这一行为的概念。揭示了不同类型的材料，特别是铝和镁在挤压过程中各向异性性能的发展。然而，根据合金和几何形状的不同，它的数量可能会有所不同。提出了一种控制挤压模内材料流动的新方法，即通过特定和可测量地影响和减小力学性能的各向异性来控制挤压模内的材料流动。通过一种新的挤压模具设计和采用添加制造技术生产挤压模具，实现了控制材料流动的可能性。材料的力学性能受到材料定向流动和相关微观结构发展的特殊影响。在结晶学水平上，这种变形产生不同的织构，因此由于激活的变形机制的方向性，导致挤压型材的各向异性力学性能。因此，可以描述和控制模具中材料流动的目标适应以及在成形过程中产生的应力和应变状态的变化。这使得有可能为有针对性地降低挤压型材的各向异性力学行为所需的微观结构发展定义设计指南。

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.