The Influence of Dispersedly Distributed Cracks on Critical Current of the Nb3Sn Strand

Original Paper
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Abstract

The Nb3Sn strand is the presently most widely used high field superconductor. However, one important fact is that the transport properties of an Nb3Sn strand will degrade obviously when it is subjected to high mechanical loads. Based on the dispersed distribution of cracks in the bronze strand due to a high axial tensile strain, we propose an analytical strand model to describe the influence of cracks on the critical current of the Nb3Sn strand. The dependence of the critical current I c of the strand on crack density is investigated theoretically. It is shown that the calculation results by this model agree with the experimental data. The influence of filament-to-matrix resistance r c on transport degradation is also discussed since r c is a key parameter for the total voltage calculation and its realistic value is of great importance for accurate results. We also compared the influence of dispersed and collective cracks on transport properties with specific conditions.

Keywords

Nb3Sn strand Dispersed distribution Crack density Filament-to-matrix resistance Critical current density 

References

  1. 1.
    Martovetsky, N., Michael, P., Minervini, J., Radovinsky, A.: ITER CS model coil and CS insert test results. IEEE Trans. Appl. Supercond. 11(1), 2030–2033 (2001)CrossRefGoogle Scholar
  2. 2.
    Pyon, T., Kanithi, H.: Development of Nb3Sn conductors for fusion and high energy physics. IEEE Trans. Appl. Supercond. 13(2), 3474–3477 (2003)CrossRefGoogle Scholar
  3. 3.
    Parrell, J.A., Field, M.B., Zhang, Y., Hong, S.: Advances in Nb3Sn strand for fusion and particle accelerator applications. IEEE Trans. Appl. Supercond. 15(2), 1200–1204 (2005)CrossRefGoogle Scholar
  4. 4.
    Luhman, T., Suenaga, M., Welch, D., Kaiho, K.: Degradation mechanism of Nb3Sn composite wires under tensile strain at 4.2K. IEEE Trans. Magn. 15(1), 699–702 (1978)ADSCrossRefGoogle Scholar
  5. 5.
    Sheth, M.K., Lee, P.J., Mcrae, D.M., Sanabria, C.M., Starch, W.L., Walsh, R.P., Jewell, M.C., Devred, A., Larbalestier, D.C.: Study of filament cracking under uniaxial repeated loading for ITER TF strands. IEEE Trans. Appl. Supercond. 22(3), 4802504–4802504 (2012)CrossRefGoogle Scholar
  6. 6.
    Sheth, M.K., Lee, P., McRae, D.M., Walsh, R., Starch, W.L., Jewell, M.C., Devred, A., Larbalestier, D.C.: Procedures for evaluating filament cracking during fatigue testing of Nb3Sn strand, pp. 201–208.  https://doi.org/10.1063/1.4712097 (2012)
  7. 7.
    Senkowicz, B.J., Takayasu, M., Lee, P.J., Minervini, J.V., Larbalestier, D.C.: Effects of bending on cracking and critical current of Nb3Sn ITER wires. IEEE Trans. Appl. Supercond. 15(2), 3470–3473 (2005)CrossRefGoogle Scholar
  8. 8.
    Xue, F., Zhang, Z., Zeng, J., Gou, X.: Effect of an elliptical inclusion on critical current density of a long cylindrical high- T c superconductor. J. Supercond. Nov. Magn. 29(8), 2023–2029 (2016).  https://doi.org/10.1007/s10948-016-3534-y CrossRefGoogle Scholar
  9. 9.
    Jewell, M.C., Lee, P.J., Larbalestier, D.C.: The influence of Nb3Sn strand geometry on filament breakage under bend strain as revealed by metallography. Supercond. Sci. Technol. 16 (9), 1005–1011(1007) (2003)ADSCrossRefGoogle Scholar
  10. 10.
    Jewell, M.C.: The effect of strand architecture on the fracture propensity of Nb3Sn composite wires. University of Wisconsin, Madison (2008)Google Scholar
  11. 11.
    Miyoshi, Y., van Lanen, E.P.A., Dhallé, M.M.J., Nijhuis, A.: Distinct voltage–current characteristics of Nb3Sn strands with dispersed and collective crack distributions. Supercond. Sci. Technol. 22(8), 085009 (2009).  https://doi.org/10.1088/0953-2048/22/8/085009 ADSCrossRefGoogle Scholar
  12. 12.
    Fang, Y., Danyluk, S., Lanagan, M.T., Youngdahl, C.A., Xu, X., Numata, K.: Characterization of Ag/Bi2Sr2Can−1CunO2n+4 interfacial resistivity. Physica C Supercond. 252(3–4), 389–396 (1995)ADSCrossRefGoogle Scholar
  13. 13.
    Holúbek, T., Dhallé, M., Kováč, P.: Current transfer in MgB2 wires with different sheath materials. Supercond. Sci. Technol. 20 (3), 123–128 (2007).  https://doi.org/10.1088/0953-2048/20/3/002 ADSCrossRefGoogle Scholar
  14. 14.
    Berger, H.H.: Contact resistance and contact resistivity. J. Electrochem. Soc. 119(4), 507–514 (1972)CrossRefGoogle Scholar
  15. 15.
    Vostner, A., Salpietro, E.: Enhanced critical current densities in Nb3Sn superconductors for large magnets. Supercond. Sci. Technol. 19 (3), S90–S95 (2006).  https://doi.org/10.1088/0953-2048/19/3/012 ADSCrossRefGoogle Scholar
  16. 16.
    Boutboul, T., Abaecherli, V., Berger, G., Hampshire, D., Parrell, J., Raine, M., Readman, P., Sailer, B., Schlenga, K., Thoener, M.: European Nb3Sn superconducting strand production and characterization for ITER TF coil conductor. IEEE Trans. Appl. Supercond. 26(4), 1–4 (2016)CrossRefGoogle Scholar
  17. 17.
    Ochiai, S., Okuda, H., Fujii, N.: Tape length-dependence of critical current and n-value in coated conductor with a local crack. Mater. Trans. 55(9), 1479–1487 (2014).  https://doi.org/10.2320/matertrans.MAW201401 CrossRefGoogle Scholar
  18. 18.
    Patel, S., Haugan, T., Chen, S., Wong, F., Narumi, E., Shaw, D.T.: Predictive model for critical current density of Ag-sheathed Bi2Sr2Ca1Cu2O8 composite tapes with fabrication defects. Cryogenics 34(6), 537–542 (1994)ADSCrossRefGoogle Scholar
  19. 19.
    Wang, Y., Xiao, L., Lin, L., Xu, X., Lu, Y., Teng, Y.: Effects of local characteristics on the performance of full length Bi2223 multifilamentary tapes. Cryogenics 43(2), 71–77 (2003).  https://doi.org/10.1016/s0011-2275(03)00005-5 ADSCrossRefGoogle Scholar
  20. 20.
    Fang, Y., Danyluk, S., Lanagan, M.T.: Effects of cracks on critical current density in Ag-sheathed superconductor tape. Cryogenics 36(11), 957–962 (1996)ADSCrossRefGoogle Scholar
  21. 21.
    Shin, J.K., Ochiai, S., Okuda, H., Sugano, M., Oh, S.S.: Change of the VI curve and critical current with applied tensile strain due to cracking of filaments in Bi2223 composite tape. Supercond. Sci. Technol. 21(11), 115007 (2008).  https://doi.org/10.1088/0953-2048/21/11/115007 ADSCrossRefGoogle Scholar
  22. 22.
    Fang, Y., Danyluk, S., Cha, Y.S., Lanagan, M.T.: Modeling voltage distribution and current limit in Ag/Bi2Sr2Can−1CunO2n+4. J. Appl. Phys. 79(2), 947 (1996).  https://doi.org/10.1063/1.362694 ADSCrossRefGoogle Scholar
  23. 23.
    Taylor, D.M.J., Hampshire, D.P.: Relationship between the n-value and critical current in Nb3Sn superconducting wires exhibiting intrinsic and extrinsic behaviour. Supercond. Sci. Technol. 18(12), S297–S302 (2005).  https://doi.org/10.1088/0953-2048/18/12/012 ADSCrossRefGoogle Scholar
  24. 24.
    Bruzzone, P., Bagnasco, M., Ciazynski, D., Corte, A.D., Zenobio, A.D., Herzog, R., Ilyin, Y., Lacroix, B., Muzzi, L., Nijhuis, A.: Test results of two ITER TF conductor short samples using high current density Nb3Sn strands. IEEE Trans. Appl. Supercond. 17(2), 1370–1373 (2007)ADSCrossRefGoogle Scholar
  25. 25.
    Ishibashi, K., Wake, M., Kobayashi, M., Katase, A.: Boundary resistance in SC composite wires and cryogenic stability. Cryogenics 19(3), 161–166 (1979)ADSCrossRefGoogle Scholar
  26. 26.
    Godeke, A., Dhalle, M., Morelli, A., Stobbelaar, L., van Weeren, H., van Eck, H.J.N., Abbas, W., Nijhuis, A., den Ouden, A., ten Haken, B.: A device to investigate the axial strain dependence of the critical current density in superconductors. Rev. Sci. Instrum. 75(12), 5112–5118 (2004).  https://doi.org/10.1063/1.1819384 ADSCrossRefGoogle Scholar
  27. 27.
    Gou, X., Schwartz, J.: Fractal analysis of the role of the rough interface between Bi2Sr2CaCu2Ox filaments and the Ag matrix in the mechanical behavior of composite round wires. Supercond. Sci. Technol. 26(5), 055016 (2013).  https://doi.org/10.1088/0953-2048/26/5/055016 ADSCrossRefGoogle Scholar
  28. 28.
    Cha, Y.S., Lanagan, M.T., Gray, K.E., Jankus, V.Z., Fang, Y.: Analysis and interpretation of critical current experiments for bismuth-based high-temperature superconductors made by powder-in-tube processing. Appl. Supercond. 2(1), 47–59 (1994)CrossRefGoogle Scholar

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© Springer Science+Business Media, LLC 2017

Authors and Affiliations

  1. 1.College of Mechanics and MaterialsHohai UniversityNanjingChina

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