Centrale Nantes and SNCF have produced a train part with additive manufacturing (AM).
Within the scope of its national AM project, the SNCF (Rolling Stock Engineering division) called upon Centrale Nantes's expertise to study the feasibility of producing certain components. The production of a pivot, an interconnecting part, by AM opens up new avenues for the design of metallic components.
"AM technologies are of interest in maintenance management in the quest to overcome supply issues and to better manage parts obsolescence, product end-of-life or the slow turnover of components produced traditionally via casting," said a spokesperson.
Following SNCF's study of Selective Laser Melting (SLM) technology for metallic materials, the project moved on to assess other manufacturing methods by adding material such as Wire Arc Additive Manufacturing (WAAM) in order to broaden the panel of suitable parts towards larger components and repair.
In 2020, Centrale Nantes and Naval Group used this technology to print the first hollow propeller blade demonstrator. This prompted Laëtitia Kirschner, AM Project Manager at SNCF Voyageurs, to get in touch with Professor Jean-Yves Hascoët, Head of the Rapid Manufacturing Platform at Centrale Nantes.
After analyzing the geometries and constraints of a catalog of possible components, Centrale Nantes and SNCF opted to use AM to produce a pivot, a part that connects the bogie to the carriage.
Centrale Nantes worked on this part, also producing a number of specimens for analysis at SNCF, in order to monitor material integrity, which involved the participation of mechanics specialists and metallurgists in the study. The promising results obtained (metallurgy, mechanical characteristics, etc.) on these specimens and tomography on the part itself were sufficiently convincing to proceed to dynamic testing. Given the green light, the part was then submitted to the test bench at the Agence d'Essai Ferroviaire, where it performed successfully under fatigue.
Based on this first study, other projects are in the pipeline for 2021.
Hascoët said, "The collaboration between the laboratory and the SNCF is very encouraging, especially with regard to the input of AM for maintenance applications. This first step, in this field, raises many opportunities for both establishments."
Kirschner said, "WAAM technology is a new milestone for us on the road towards the repair and maintainability of large parts via AM. Our fruitful collaboration with Centrale Nantes has made this achievement possible."
For more information contact:
Centrale Nantes
www.ec-nantes.fr