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Formation of Porosity and Its Effects on the Uniformity of Jc in Bi-2212/Ag Tapes

  • W. Zhang
  • M. Polak
  • A. Polyanskii
  • E. E. Hellstrom
  • D. C. Larbalestier
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 44)

Abstract

The uniformity of Bi-2212 tape has been studied by using multiple potential taps, Magneto-Optical (MO) imaging and microstructure observation. The major defect, porosity, has been identified in the melt processed tapes. The current sharing into the Ag sheath due to the existence of defects causes a linear section on the V-I curve. The cause of the porosity formation is believed to be due to the gas release, such as CO2, when 2212 reforms from the liquid phase. Some other factors which can influence the porosity formation, such as packing density, packing atmosphere and pre-heat treatment of billets have also been examined.

Keywords

Packing Density Bubble Formation Precursor Powder Porosity Formation Oxide Core 
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.
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Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • W. Zhang
    • 1
  • M. Polak
    • 1
  • A. Polyanskii
    • 1
  • E. E. Hellstrom
    • 1
  • D. C. Larbalestier
    • 1
  1. 1.Applied Superconductivity CenterUniversity of Wisconsin-MadisonMadisonUSA

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