Processing and fabrication of YBa2Cu3O(x)/Ag composite wires and coils
Abstract
Silver was added to YBa2Cu3O(x) (123) powder by a melt technique using AgNO3 and heated to approx. 600 C to decompose the nitrate. This process yields 123 powder that is uniformly coated with Ag, as indicated by optical and scanning electron microscopy (SEM). The composite power is formed into rods (approx. 4 mm diameter) via drawing and swaging through conical converging dies. Wires of finer diameter (approx. 1 mm) and substantially greater linear uniformity were produced by slurry extrusion of the composite powder in a polymeric vehicle. Transport critical current density, J sub c, of these wires at present is about 750 A/sq cm. This value may be expected to rise due to further reduction of second phase impurities localized at grain boundaries and better understanding of the Ag/superconductor interface. The wire fabrication is described in some detail and discusses the results of microscopic analyses by scanning electron microscopy (SEM), x ray photoemission spectroscopy (XPS), and x ray diffraction (XRD).
- Publication:
-
Presented at the 2nd International Ceramic Science and Technology Congress
- Pub Date:
- November 1990
- Bibcode:
- 1990icst.cong...12F
- Keywords:
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- Copper Oxides;
- Grain Boundaries;
- High Temperature Superconductors;
- Microstructure;
- Silver;
- Wire;
- Barium Oxides;
- Critical Temperature;
- Current Density;
- Fabrication;
- Forming Techniques;
- X Ray Diffraction;
- X Ray Spectra;
- Yttrium Oxides;
- Solid-State Physics