Microstructural characterization of Nb3Al ultrafine multifilamentary superconducting wire by analytical electron microscopy
Abstract
Microstructural characterization of the longitudinal cross section of Nb3Al wires fabricated by an Nb tube composite process is presented. The wire was produced by cold reduction and a subsequent reaction between Nb matrix and Al-Mg core (final size: ∼φ 80 nm) at 950 °C×5 min+750 °C×72 h. The A15 superconducting compound (grain size: 100 nm) and unreacted fibrous Nb were observed in the microstructure. Nb2Al or other phases rarely appeared. The average Al concentration at the A15 grain was 22-23 at. % from x-ray microanalysis. The critical current density Jc of composite processed wire depended on the grain size of A15, with fine grains providing a high Jc value.
- Publication:
-
Applied Physics Letters
- Pub Date:
- July 1991
- DOI:
- Bibcode:
- 1991ApPhL..59..473W
- Keywords:
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- Aluminum Alloys;
- Electric Wire;
- Electron Microscopy;
- Microstructure;
- Niobium Alloys;
- Superconductors;
- Critical Temperature;
- Current Density;
- Grain Size;
- Heat Treatment;
- Intermetallics;
- Phase Transformations;
- Solid-State Physics