Joining by forming of two-shear aluminum-steel-joints by shear-clinching

• Applicant: Professorin Dr.-Ing. Marion Merklein
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing ; Joining and Separation Technology
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 497635767

Besides the use lightweight materials, the lightweight principle is realized by function integration and the load-specific design of components. This requires the joining of dissimilar materials as well as the joining of multi-layer sheets. Latter is a challenge, not only for welding technologies, but also for mechanical joining processes, since the additional sheet layer and contact surface obstructs the process design. Process limits of well-established mechanical joining processes also apply for the joining of multi-layer sheets. Therefore, high-strength material can only be joined with additional fasteners. Moreover, there are no systematic investigations on the influence of the mechanical properties of the joining partners, their thickness and the order for the joining by forming of multi-layer sheets. Therefore, the aim of the research project is the enhancement of process limits of joining by forming of dissimilar, multi-layer materials through the qualification of the shear-clinching technology for the joining of three-layer sheets. For this purpose, the shear-clinching process is fundamentally investigated for the joining of two-shear joints and the basic mechanisms are derived. The effect of the additional sheet is systematically analyzed in dependence of influences from the mechanical properties of the joining partners and the tool geometry. By the analysis of the cutting behavior and the material flow, the interaction of each layer is identified, laying the foundation for the adaption of prevailing tool systems for the changed process conditions. The suitability of the solution is confirmed by the analysis of the joint characteristics.

• DFG Programme: Research Grants