Speaker
Yoshimitsu Hishinuma
(National Institute for Fusion Science)
Description
The degradation of transport current property by the high mechanical strain on the practical Nb3Sn wire is serious problem to apply for the future fusion magnet operated under higher electromagnetic force environment beyond ITER. Recently, we approached to the solid solution ternary Cu-Sn (Cu-Sn-X) matrices for the development of the high mechanical strength bronze processed Nb3Sn wires. Generally, it is well known that Zn has the larger solubility limit against the Cu compared with Sn. In the various Nb/Cu-Sn-Zn composite precursors, we confirmed that Zn remained homogeneously into the matrices after the Nb3Sn layer synthesis. The Cu-Sn-Zn ternary alloy was one of the interesting bronze materials for the high strengthened Nb3Sn wires.
We fabricated the bronze processed Nb3Sn multifilamentary wires using various Cu-Sn-Zn matrices. In these multifilamentary wires, Zn remained into the matrices after the Nb3Sn synthesis, and then the Vickers hardness of the Cu-Sn-Zn matrices after the Nb3Sn synthesis heat treatment was higher than that of the conventional bronze matrix. Higher Vickers hardness caused by the Cu-Zn phase formation in the matrix.
In this study, microstructure and superconducting properties of the bronze processed Nb3Sn multifilamentary wires using various Cu-Sn-Zn matrices were mainly reported. In addition, comparisons of the mechanical properties on the Nb3Sn wires with different Cu-Sn-Zn matrices were also reported. Especially, transport Ic behavior by applying the tensile strain on the Nb3Sn multifilamtary wire using various Cu-Sn-Zn matrices was investigated.
This work mainly performed to the Fusion Engineering Research Project (UFFF036) and the collaboration program (KECF013) in NIFS, and also supported by the High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University (No.15H0024).
Co-authors
Akihiro Kikuchi
(National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Japan)
Hidetoshi Oguro
(High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, Japan)
Hiroyasu Taniguchi
(Osaka Alloying Works Co.,Ltd, 45-5-9 Shirakata ,Fukui, Japan)
Yoshimitsu Hishinuma
(National Institute for Fusion Science, 322-6, Oroshi-cho, Toki, Japan)
