TY - JOUR
T1 - Prebending strain effect on CuNb/Nb3Sn superconducting wire during practical react-and-wind process
AU - Nishijima, Gen
AU - Oguro, Hidetoshi
AU - Awaji, Satoshi
AU - Watanabe, Kazuo
AU - Katagiri, Kazumune
AU - Miyoshi, Kazutomi
AU - Meguro, Shin Ichiro
N1 - Funding Information:
Manuscript received September 20, 2005. This work was supported by Industrial Technology Research Grant Program in 2004 from New Energy and Industrial Technology Development Organization (NEDO) of Japan, and Grant-in-Aid for Scientific Research (B) from the Ministry of Education, Science and Technology, Japan.
PY - 2006/6
Y1 - 2006/6
N2 - To demonstrate the applicability of the prebending strain effect to the R&W coil winding process, we have developed the prebent react-and-wind (R&W) process, which is the combination of the conventional R&W process and the prebending treatment. The superconducting and mechanical characteristics were investigated for CuNb/Nb3Sn superconducting wires which were picked up from the prebent R&W coil winding process. The results were compared with that of CuNb/Nb3Sn wires which were prebent manually using a prebending former. The prebending treatment using pulleys enhanced Ic more than the manual prebending treatment. This is explained qualitatively by a difference of the prebending strain distribution. The prebending strain distribution is plain symmetric and axis symmetric in cases of the manual prebending and the pulleyed prebending, respectively. The axis symmetrically distributed prebending strain reduces the residual strain more than the plain symmetrical one. The mechanical property was also enhanced. The slope of the stress-strain curve for the pulleyed prebent samples were steeper than that of as-heat-treated sample. The maximum Ic of the I c-strain curve was enhanced and the strain value corresponding to the maximum Ic shifted to smaller strain by the pulleyed prebending treatment. Though in the large stress region over 200 MPa, the I c-stress curves of pulleyed prebent samples and as-heat-treated sample were in good agreement, suggesting that the Ic enhancement effect by the prebending treatment was not beneficial, in the small stress region, it is quite beneficial.
AB - To demonstrate the applicability of the prebending strain effect to the R&W coil winding process, we have developed the prebent react-and-wind (R&W) process, which is the combination of the conventional R&W process and the prebending treatment. The superconducting and mechanical characteristics were investigated for CuNb/Nb3Sn superconducting wires which were picked up from the prebent R&W coil winding process. The results were compared with that of CuNb/Nb3Sn wires which were prebent manually using a prebending former. The prebending treatment using pulleys enhanced Ic more than the manual prebending treatment. This is explained qualitatively by a difference of the prebending strain distribution. The prebending strain distribution is plain symmetric and axis symmetric in cases of the manual prebending and the pulleyed prebending, respectively. The axis symmetrically distributed prebending strain reduces the residual strain more than the plain symmetrical one. The mechanical property was also enhanced. The slope of the stress-strain curve for the pulleyed prebent samples were steeper than that of as-heat-treated sample. The maximum Ic of the I c-strain curve was enhanced and the strain value corresponding to the maximum Ic shifted to smaller strain by the pulleyed prebending treatment. Though in the large stress region over 200 MPa, the I c-stress curves of pulleyed prebent samples and as-heat-treated sample were in good agreement, suggesting that the Ic enhancement effect by the prebending treatment was not beneficial, in the small stress region, it is quite beneficial.
KW - Critical current
KW - CuNb/NbSn superconducting wire
KW - Mechanical property
KW - Prebending strain effect
KW - React-and-wind process
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U2 - 10.1109/TASC.2006.870004
DO - 10.1109/TASC.2006.870004
M3 - Article
AN - SCOPUS:33746656756
VL - 16
SP - 1220
EP - 1223
JO - IEEE Transactions on Applied Superconductivity
JF - IEEE Transactions on Applied Superconductivity
SN - 1051-8223
IS - 2
M1 - 1643069
ER -