Increase of the electrode life during resistance spot welding of aluminium alloys by application of diffusion barrier layers

• Applicants: Professor Dr. Harald Schmidt; Professor Dr.-Ing. Volker Wesling
• Subject Area: Joining and Separation Technology
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 464385838

The planned project comprises the investigation of degradation mechanisms of electrode caps during resistance spot welding of aluminium materials and the development of shutdown mechanisms by generating diffusion barrier layer-structuring combinations.Fundamental processes of the degradation mechanisms can be described by combined effects of diffusion processes as well as mechanical overload of local material areas of intermetallic phase regions in the interface area electrode cap - aluminium sheet. The scientific starting point is the suppression of diffusion processes between base material and electrode cap by application of thin film layers in the μm range, supported by a coordinated current density and thermal management via the electrode cap structuring. Furthermore, this research project aims to achieve a profound understanding and consistent picture of the degradation process by deriving a dedicated model of the degradation and wear behavior. As a result a significant increase of the electrode life is expected, which will further increase the efficiency of this joining process in the field of aluminium materials.For the successful execution of the investigations planned in the project, the basic research-oriented working group Schmidt and the application-oriented working group Wesling work together in an interdisciplinary way. The methodical approach / coupling point for the clarification of the diffusion behaviour as well as for the layer and structure development are different isochronous and isothermal model experiments, combined with statistically verified experimental welding experiments.

• DFG Programme: Research Grants