Effects of Hot Rolling on Powder-in-Tube BSCCO Tapes

  • J. Guo
  • J. Schwartz
  • Y. S. Cha
  • C.-T. Wu
  • K. C. Goretta
Part of the An International Cryogenic Materials Conference Publication book series (ACRE, volume 40)

Abstract

High critical currents have been obtained in Bi-Sr-Ca-Cu-O (BSCCO) by the powderin-tube approach. Because of the inherent structural anisotropy of the Bi-based high-Tc superconducting materials, high-Jc is obtained only when the wires are subsequently rolled into rectangularly cross-sectioned tapes. Previously, intermediate annealing was employed to maintain ductility in the silver, with a high-temperature sintering just before the final rolling in order to form the high-Tc, superconducting phase. Here, we report on the effects of hot rolling at various temperatures for the final rolling of powder-in-tube BSCCO-2212 tapes. Hot rolling was accomplished by preheating the rolls with infrared heaters and rolling the tapes directly from the furnace. The highest current densities were obtained by a final hot rolling of the 2212 tapes at 420°C, with the furnace temperature at 750°C (the highest temperature studied). Results showed that the enhancement of Jc was due to the improvement of grain alignment, as well as to the reduction of the size and fraction of Bi-free phases during the final heat treatment. Furthermore, an analytical model of the hot-rolling process that has been developed illustrates the importance of preheating the tapes and heating the rolls.

Keywords

Partial Melting High Current Density Critical Current Density Longitudinal Cross Section Final Rolling 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    C.-T. Wu, K.C. Goretta, and R.B. Poeppel, Appi. Supercond. Vol. 1, No. 1 /2, (1993) 33–42.Google Scholar
  2. 2.
    H. Sehne et al., J. Appi. Phys. 70(3), 1 August 1991, p1596.Google Scholar
  3. 3.
    H. Kumakura et al., Appl. Phys. Lett. 58(24), 17 June 1991, p2830.Google Scholar
  4. 4.
    J. Kase et al., Trans. Magn. 27 (1991) 1254.CrossRefGoogle Scholar
  5. 5.
    Y. Feng et al., Physica C 192 (1992) 293–305.CrossRefGoogle Scholar
  6. 6.
    M.J. McGuire et al., Ceram. Trans. (1991) 18: 453.Google Scholar
  7. 7.
    C.P. Bean, Phys. Rev. Lett. 8 (1962) 250.CrossRefGoogle Scholar
  8. 8.
    Y.S. Touloukian et al., M. C., 1973, ( IFI/Plenum, New York).Google Scholar
  9. 9.
    J. Issac, J. Philip, M.T. Sebastian, and A.D. Damoda, Physica C, (1992) 199: 247.CrossRefGoogle Scholar
  10. 10.
    H.S. Carslaw et al., (Oxford Press, Oxford, England ), (1980) 100–101.Google Scholar
  11. 11.
    J.L. Routbort et al., J. Mater. Res. (1992) 7: 2360.CrossRefGoogle Scholar
  12. 12.
    K.C. Goretta and J.L. Routbort, unpublished results, 1993.Google Scholar

Copyright information

© Springer Science+Business Media New York 1994

Authors and Affiliations

  • J. Guo
    • 1
  • J. Schwartz
    • 1
  • Y. S. Cha
    • 2
  • C.-T. Wu
    • 2
  • K. C. Goretta
    • 2
  1. 1.Department of Nuclear EngineeringUniversity of Illinois at Urbana-ChampaignUrbanaUSA
  2. 2.Energy Technology DivisionArgonne National LaboratoryArgonneUSA

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