Abstract
The mechanical performance at cryogenic temperature and the degradation mechanism of electric behaviors of Bi-2222/Ag tapes with different protective layers as well as their contradiction laws are discussed. A variable temperature cryostat system is constructed to provide the successive cooling environment from room temperature (RT) to the liquid nitrogen temperature (LNT), and a cryogenic-type extensometer is also used to measure strain behavior of the superconducting tapes. And, the effects of bending strain on the critical current of Bi-2222/Ag tapes with different protective layer were measured using arched abrasives with different radius. Experimented results have shown that the protective layer of the tapes could have strong positive effects on the measured mechanical performance at room temperature and cryogenic temperature. The irreversible degradation on strain indicates that the I c reduction is caused mainly by crack formation and propagation in the brittle Bi-2222/Ag tapes. In particular, the degradation mechanism of multifilamentary sample with protective layer was also elaborated, and protective layer has some negative effect on electric behaviors. In addition, the behaviors of the n value with strains on standard Bi2222/Ag tape was also argued to predict the damage process in Bi-2222 tapes indirectly during bending tests.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ahorantaa, M., Lehtonen, J., Tarhasaari, T.: Influence of tape-specific properties on local stress and strain in Bi-2222/Ag tapes. Physica. C 470, 257–261 (2010)
Shin, H., Katagiri, K.: Critical current degradation behaviour in Bi-2222 superconducting tapes under bending and torsion strains. Supercond. Sci. Technol. 16, 1012–1018 (2003)
Kovác, P., Bukva, P.: Differences in applied axial strain and Ic degradation of Bi(2223)/Ag tapes Supercond. Sci. Technol. 14, 8–11 (2001)
Sun, S.J., Liu, W., Chen, X.P., Li, M.Y., Han, Z.: Effect of bending strain on the critical current of Bi-2222/Ag tapes with different structures Supercond. Sci. Technol. 16, 984–987 (2003)
Shin, H., Dizon, J.R.C., Kim, K., Oh, S., Ha, D.: Ic degradation behaviors of Bi-2222 superconducting tapes under axial fatigue loading. Cryogenics 46, 378–384 (2006)
Miyoshi, Y., Kitaguchi, H., Chaud, X., Debray, F., Nishijima, G., Tsuchiya, Y.: Homogeneous performance and strain tolerance of long Bi-2222 HTS conductors under hoop stress. Supercond. Sci. Technol. 16, 1012–1018 (2003)
Nakashima, T., Kobayashi, S., Kagiyama, T., Yamazaki, K., Kikuchi, M., Yamade, S., Hayashi, K., Sato, K., Osabe, G., Fujikami, J.: Overview of the recent performance of DI-BSCCO wire. Cryogenics 52, 713–718 (2012)
Xiao, L.Y., Hilton, D.K., Hascicek, Y.S., Van Sciver, S.W.: Mechanical tests on the surface-coated Bi-2212 superconducting tapes. Cryogenics 37, 837–841 (1997)
Choi, S., Kiyoshi, T., Hahn, S.Y., Sugano, M.: Stress analysis of a high temperature superconductor coil wound with Bi-2222/Ag tapes for high field HTS/LTS NMR magnet application. IEEE Trans. Appl. Supercond. 19(3), 989–992 (2009)
Acknowledgments
The authors would like to acknowledge the supports by the National Natural Science Foundation of China (11302225), the State Key Program of National Natural Science Foundation of China (11032006), and the Foundation for Innovative Research Groups of NNSFC (11121202).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Guan, M., Wang, X., Xin, C. et al. The Contradiction Behavior Between Mechanical Performance and Degradation Mechanism of Electric at Cryogenic Temperature in Bi-2222/Ag Tapes with Different Protective Layer. J Supercond Nov Magn 27, 2257–2262 (2014). https://doi.org/10.1007/s10948-014-2581-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10948-014-2581-5