Studies on the reproducibility of the magnetic pulse welding in the case of an asymmetric impact

• Applicant: Professor Dr.-Ing. Stefan Böhm
• Subject Area: Production Automation and Assembly Technology
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 323203464

The aim of this research subject is to ensure the robustness and design of the properties of the welded joint for magnetic pulse welding. Here, research is based partly on physical process variables which had already been determined for impact welding (e.g. collision angle and collision point velocity) and the description of the lower weld seam boundary. According to the latest state of the art and own research, specific changes in the surface topography enable an enlargement of the welding window and allow to set the properties of the joint. Furthermore, the research has shown that, in conjunction with certain process parameters (e.g. influence of the acceleration distance on the collision angle as well as the regulation of the current), the jet formation can be influenced, which, in turn, effects the morphology of the welded joint (wavy or flat interface, phase formation). This research project also aims to determine and secure the mechanical properties of magnetic pulse welds (cyclical and dynamic load) with regard to the morphology of the weld and wants to examine the influence of high process velocities on hardening in the welding zone after plastic deformation. In order to evaluate the quality of the weld seam, the surface of the weld seam will be established as a quality feature for magnetic pulse welds and will then be correlated to the physical process variables. Another important focus will be the determination of the energy balance so that the results can be transferred to other material combinations. Depending on the topic, tests will be performed in cooperation with the project A5 (PTU, collision welding) as well as A8 (IWW, microstructural mechanisms). In addition, there will also be a cooperation with the project A3 (MPIE, surface chemistry) and, finally, the influence of the oxide layer will be examined.The acquired results will enable a product design suitable for welding with a layout of the properties of the welded joint which is flexible, in order to suit specific applications. Additionally, in cooperation with the project A5, these results shall support the prediction of the properties of the joint via numeric simulations.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1640: Joining by Plastic Deformation