Fraunhofer Institute for Production Technology IPTResearch project "LEDA"
Shifting freight and passenger traffic to rail is a fundamental step toward achieving the German government's goal of greenhouse gas neutrality by 2045. Indeed, the industry needs to increase its economic efficiency to establish rail as an ecologically and economically more attractive alternative to private transportation. Reducing the effort and cost of maintaining rail vehicles, especially components critical to safety, such as wheels, is an important factor.
Innovative process chain for repairing railway wheels
Railway wheels are subject to strict safety requirements and require regular repairs due to the high material stress. Typically, the wheels are manufactured with a certain amount of material added, and then during repair, material is removed by subtractive processes until the surface is flawless again. This approach is neither economical nor efficient.
In the research project "LEDA - Extending the service life of railway wheels through wire-based metal deposition," Fraunhofer IPT is developing an innovative process chain for the repair of railway wheels. Since it uses additive manufacturing technologies selectively, this process chain is significantly more economically and ecologically efficient than conventional methods.
New process chain triples service life of railway wheels
The new process chain detects and analyzes defects, automatically selects the optimal repair strategy, then repairs the parts using additive processes, subtractive pre- and post-processing, and finally does a comprehensive quality control and assurance.
The use of additive manufacturing processes is revolutionizing the repair of railway wheels: Instead of removing material, additional material is applied using additive processes. This triples wheel life and significantly reduces material consumption, maintenance costs and downtime. The ability to automate repairs is increased, and the weight of the wheels is reduced, resulting in lower transportation costs.
Software solutions for automation and comprehensive quality control
The research team at Fraunhofer IPT first identifies the optimal material for the wire and the best possible method for additive repair. Different materials will be tested using laser metal deposition with wire (LMD-w) and wire arc additive manufacturing (WAAM), and the results will be compared.
To automate the repair processes, the project team is developing various software tools, such as scanning strategies for precise defect detection and a CAD/CAM module for standardized path planning. The developed software tools will be integrated into an existing software environment.
The entire process chain is subject to comprehensive quality control. This is ensured by a monitoring system and non-destructive testing methods. The repaired wheels are intensively tested both in the field and on test stands to verify the repaired quality.
Feasibility study for approval of deposition-based repair process
In the final phase of the project, the researchers will evaluate the new repair process chain in its entirety and analyze its suitability for future approval. This approach will help them make a technically sound statement, at the end of the project, on how reliable the additive repair process is and how stable it is expect to be in long-term. Based on the results of the joint project "LEDA," they will prepare a feasibility study for the approval of the deposition-based repair process. This will take into account the ecological and economic added value.
Funding
The project "LEDA – Service life extension of railroad wheels through wire-based metal deposition" is funded by the Federal Ministry for Economic Affairs and Climate Protection as part of the 7th Energy Research Program "Innovations for the Energy Transition."
Project management organization: Project Management Jülich
Project partners
- Fraunhofer IPT (Coordination)
- Chair and Institute for Rail Vehicles and Transportation Systems at RWTH Aachen University
- ModuleWorks GmbH, Aachen
- Hegenscheidt-MFD GmbH, Erkelenz
- Rurtalbahn GmbH, Düren
Associated partner: Deutsche Bahn AG