Production of bead-shaped parts by cold extrusion of semi-finished products fabricated by composite hot extrusion

不同材料的组合在成形过程中可用于调整新产品的性能，如局部提高强度或耐磨性、耐热性或导电性。在连续复合挤压的研究中，铝基与钢丝之间形成了一种材料结合。在具有不连续增强单元的复合材料挤压研究中，仅通过光学显微图像检测嵌入质量。对于非连续复合挤压工艺，尚未对复合材料的材料结合进行研究。此外，没有定义几何和材料要求，特别是单个复合材料伙伴的强度关系。到目前为止，复合材料侧向挤压的研究主要集中在产生一种形状配合。对复合挤压和复合侧向挤压的研究现状和自己的初步工作的分析表明，存在以下知识缺陷。对断续挤压复合材料后工艺参数对材料粘结的影响尚未进行研究。此外，对于复合挤压生产的半成品的附面层在复合侧向挤压后对构件附面层的影响尚不了解。这些知识的不足证明了本研究项目的重点是将功能或增强元件以管的形式从具有相同或更高强度的材料中挤出，并在铝基体中使用铝芯，并通过复合镦压或复合侧向挤压工艺对混合半成品进行后续加工。研究需要澄清与不连续复合挤压及随后的复合镦粗或复合侧向挤压工艺设计相关的未知材料、几何、表面物理和成形相互作用，以及所生成的混杂部件的性能。

The combination of different materials in the forming process can be used to adjust new product properties, such as the local increase of strength or wear resistance, heat or electrical conductivity. In studies on continuous composite extrusion, a material bond between aluminum matrix and steel wire could be produced. In investigations on composite extrusion with discontinuous reinforcement elements, only the quality of the embedding was examined by light microscopic images. Investigations on a material bond of the composite partners have not yet taken place for discontinuous composite extrusion process. In addition, no geometric and material requirements, in particular the relation of the strength of individual composite partners, were defined. Until now, research on composite lateral extrusion has focused on producing a form fit. The analysis of the state of research and the own preliminary work on composite extrusion and composite lateral extrusion show the following knowledge deficits. The influencing process parameters on the material bond after the discontinuous composite extrusion have not been explored. Furthermore, there is no knowledge about the influence of the boundary layer of the semifinished product produced by composite extrusion on the boundary layer of the component after the composite lateral extrusion. These knowledge deficits justify the focus of this research project on the composite extrusion of functional or reinforcing elements in the form of tubes out of material with the same or higher strength with an aluminum core in an aluminum matrix and the subsequent processing of the hybrid semifinished product by a composite upsetting or composite lateral extrusion process. The research needs to clarify the unknown material, geometric, surface-physical and forming interactions in relation to the process design of discontinuous composite extrusion and subsequent composite upsetting or composite lateral extrusion as well as on the properties of the generated hybrid component.