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

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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.