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Journal of Materials Shaping Technology

, Volume 7, Issue 4, pp 193–198 | Cite as

Rapid consolidation of YBa2Cu3O7 powder

  • Patrick Tibbits
  • Sun Keyi
Article

Abstract

Electrical current in a powder transits particle contact points, whose high resistance localizesI2R heating. The occurrence of sintering at particle contact points suggests an efficient means of consolidating the difficult-to-sinter ceramic superconductor YBa2Cu3O7.

A specially fabricated apparatus for simultaneous application of pressure and passage of electrical current accomplished the consolidation. Computerized control continuously adjusted current levels for changes in specimen resistance, maintaining a constant level of power dissipation. Power dissipation of 55 W for one minute produced solid specimens, either cylinders 3 mm in diameter x 4 mm, or blocks 2 mm x 5 mm x 5 mm. The specimens were annealed in flowing oxygen, save for one control.

Annealed specimens exhibited Meissner effect, transition to zero resistivity near 90 K, andjc 75 A/cm2. The scanning electron microscope (SEM) showed porous microstructures for all but one specimen. The control had a similar microstructure, showing annealing added little consolidation. This work demonstrates the rapid consolidation of YBa2Cu3O7 powder into a solid which upon oxygen annealing exhibits true superconductivity.

Keywords

Power Dissipation Critical Current Density Ohmic Heating Load Frame Material Shaping Technology 
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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Copyright information

© Springer-Verlag New York Inc 1989

Authors and Affiliations

  • Patrick Tibbits
    • 1
  • Sun Keyi
    • 1
  1. 1.Texas Center for SuperconductivityUniversity of HoustonHoustonUSA

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