Two teams from LNCMI, located in Grenoble and Toulouse, are gathering their skills and share their involvement to support the development of new conductors for both DC and pulsed high magnetic fields. The key to success is to add very small content of silver in a copper based materials and tailor the appropriate micro/nanostructuration of the conductor by mastering the innovative successive process steps of powder metallurgy, cold-spray and wire-drawing.High-strength, high-conductivity copper/silver-alloyed materials are prepared by cold-spray (CS) manufacturing at ICB-LERMPS in Belfort (FR).For DC high-field application at room temperature, bulk Cu/Ag (5% vol. Ag) alloys with high mechanical properties and high electrical conductivity can be obtained by CS and post-heat treatments. The Cu/Ag-alloyed bulk CS deposit presents a high yield strength of about 510 MPa with a corresponding electrical resistivity of 1.92 µΩ.cm (at 293 K).
For pulsed-field application at liquid nitrogen temperature, bulk Cu/Ag (5% vol. Ag) alloys serve as precursors for room-temperature wire drawing. The Cu/Ag-alloyed wires show a very high ultimate tensile strength (1660 MPa at 77 K) and low electrical resistivity (1.05 µΩ.cm at 77 K).
Microstructural studies, performed in Institut Pprime in Poitiers, via STEM allow to understand this very high level of mechanical strength. The results evidence that materials developed by CS exhibit very high mechanical properties compared to materials prepared by other routes, due to the high velocity of the deposited particles, which leads to high initial deformation rates and specific microstructural features.
Publication : High-Strength Copper/Silver Alloys Processed by Cold Spraying for DC and Pulsed High Magnetic Fields; Simon Tardieu, Hanane Idrir, Christophe Verdy, Olivier Jay, Nelson Ferreira, François Debray, Anne Joulain, Christophe Tromas, Ludovic Thilly and Florence Lecouturier-DupouyMagnetochemistry as part of the Special Issue Feature Papers in Materials for High Field Resistive Magnets, Magnetochemistry 2024, 10(3), 15, https://doi.org/10.3390/magnetochemistry10030015
Contact: simon.tardieu@lncmi.cnrs.fr, olivier.jay@lncmi.cnrs.fr, francois.debray@lncmi.cnrs.fr, florence.lecouturier@lncmi.cnrs.fr