TY - JOUR A1 - Scheuerlein, C. A1 - Fedelich, Bernard A1 - Alknes, P. A1 - Arnau, G. A1 - Bjoerstad, R. A1 - Bordini, B. T1 - Elastic anisotropy in multifilament Nb3Sn superconducting wires JF - IEEE transactions on applied superconductivity N2 - The elastic anisotropy caused by the texture in the Nb3Sn filaments of PIT and RRP wires has been calculated by averaging the estimates of Voigt and Reuss, using published Nb3Sn single crystal elastic constants and the Nb3Sn grain orientation distribution determined in both wire types by Electron Backscatter Diffraction. At ambient temperature the calculated Nb3Sn E-moduli in axial direction in the PIT and the RRP wire are 130 GPa and 140 GPa, respectively. The calculated E-moduli are compared with tensile test results obtained for the corresponding wires and extracted filament bundles. KW - Anisotropy KW - EBSD KW - Elastic modulus KW - Nb3Sn KW - Tensile test KW - Texture PY - 2015 DO - https://doi.org/10.1109/TASC.2014.2371693 SN - 1051-8223 VL - 25 IS - 3 SP - 8400605-1 EP - 8400605-5 PB - Inst. CY - New York, NY, USA AN - OPUS4-32661 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scheuerlein, C. A1 - Andrieux, J. A1 - Michels, M. A1 - Lackner, F. A1 - Chiriac, R. A1 - Hagner, M. A1 - Di Michiel, M. A1 - Meyer, Christian A1 - Toche, F. ED - Foley, C. P. T1 - Effect of the fabrication route on the phase and volume changes during the reaction heat treatment of Nb3Sn superconducting wires JF - Superconductor Science and Technology N2 - Accelerator magnets that can reach magnetic fields well beyond the Nb-Ti performance limits are presently being built and developed, using Nb3Sn superconductors. This technology requires reaction heat treatment (RHT) of the magnet coils, during which Nb3Sn is formed from its ductile precursor materials (a “wind and react” approach). The Nb3Sn microstructure and microchemistry are strongly influenced by the conductor fabrication route, and by the Phase changes during RHT. By combining in situ differential scanning calorimetry, high Energy synchrotron x-ray diffraction, and micro-tomography experiments, we have acquired a unique data set that describes in great detail the phase and microstructure changes that take place during the processing of restacked rod process (RRP), powder-in-tube (PIT), and internal tin (IT) Nb3Sn wires. At temperatures below 450 ° the phase evolutions in the three wire types are similar, with respectively solid state interdiffusion of Cu and Sn, Cu6Sn5 formation, and Cu6Sn5 peritectic transformation. Distinct differences in phase evolutions in the wires are found when temperatures exceed 450 °C. The volume changes of the conductor during RHT are a difficulty in the production of Nb3Sn accelerator magnets. We compare the wire diameter changes measured in situ by dilatometry with the phase and void volume evolution of the three types of Nb3Sn wire. Unlike the Nb3Sn wire length changes, the wire diameter evolution is characteristic for each Nb3Sn wire type. The strongest volume increase, of about 5%, is observed in the RRP wire, where the main diameter increase occurs above 600 °C upon Nb3Sn formation. KW - Nb3Sn KW - Microstructure KW - Phase transformations KW - Volume changes KW - X-ray diffraction KW - Differential scanning calorimetry KW - Synchrotron micro-tomography PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505128 DO - https://doi.org/10.1088/1361-6668/ab627c VL - 33 IS - 3 SP - 034004 PB - IOP Publishing CY - Bristol (UK) AN - OPUS4-50512 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -