Fabrication and Superconducting Properties of the Bronze-Processed \mbox\mbox Multifilamentary Wire Using Cu-Sn-Zn Alloy Matrix

• Published in: IEEE transactions on applied superconductivity Vol. 25; no. 3; pp. 1 - 4
• Main Authors: Hishinuma, Y., Kikuchi, A., Taniguchi, H., Sugimoto, M., Takagi, A., Mizuta, T., Mito, T., Tachikawa, K.
• Format: Journal Article
• Language: English
• Published: IEEE 01.06.2015
• Subjects: Bronzed process; Cu-Sn-Zn alloy; Heat treatment; multifilamentary wires; Nb3Sn; Niobium-tin; Wires; Zinc; Zn addition; mbox{Nb}_{3}\mbox{Sn}; Cu–Sn–Zn alloy; multifilamentary wires; Bronzed process; Zn addition
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2014.2387053

We developed several new Cu-Sn-Zn-(Ti) alloys, which are so-called "CSZ alloy," for practical bronze-processed Nb 3 Sn wires. Several CSZ alloys were fabricated via the Mizuta method. The Zn was uniformly dissolved in the α phase of the Cu-Sn alloy, and the Zn-Ti compounds were not found in the CSZ alloy. Various 19 Nb-filament CSZ Nb 3 Sn precursor wires were fabricated using CSZ matrices with different Sn and Zn nominal compositions. We also found that the CSZ/Nb composites showed excellent workability at room temperature. In this paper, changes in microstructure and superconducting properties of Nb 3 Sn wires with different CSZ matrices as a function of the heat treatment condition were investigated. We clearly observed that the amount of Zn in the matrix remained constant after the Nb 3 Sn formation. Thicker Nb 3 Sn layers were formed by the Zn addition. T c transitions of about 18 K have been obtained. Finally, we have succeeded in fabricating multifilamentary wires using CSZ matrices through the restacking method. The number of Nb filaments is 7771 with a diameter of 3.4 μm. The effect of the Zn addition on microstructures and superconducting property of the CSZ wires are also reported.