Solid-state welding of oxide-containing aluminium surfaces in forming technology

Reliable solid-state welding of aluminium surfaces is crucial for joining technologies, lightweight fabrication, and forming processes, as well as for low-carbon recycling methods, notably chip extrusion of complex endless profiles. While hot extrusion provides a controlled method to join such surfaces, the influence of forming conditions on local weld strength remains insufficiently understood. This project produces weld seams under defined hot extrusion conditions to enable targeted joining and sampling with known seam positions. Metallographic analysis and automated shear strength testing are combined to evaluate both microstructural features and quantitative bonding strength. Complete cross-sections and localized sections of the weld are analysed to map the strength distribution across the seam and to validate a numerical model for predicting weld strength. This integrated approach supports the development of experimental methods with independently adjustable extrusion conditions and automatable evaluation procedures. It also enables the creation of predictive models for weld strength and strategies to enhance solid-state welding performance under controlled extrusion conditions.