2003年9月
Mechanical and superconducting properties of PIT-processed MgB2 wire after heat treatment
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
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- 巻
- 16
- 号
- 9
- 開始ページ
- 1052
- 終了ページ
- 1058
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1088/0953-2048/16/9/315
- 出版者・発行元
- IOP PUBLISHING LTD
The mechanical and superconducting properties of MgB2 wires heat treated at various conditions have been investigated. Superconducting MgB2 wires, fabricated by the powder-in-tube (PIT) method, show a transition temperature T-c at 32.4 K for the as-rolled wire as shown by dc-resistivity measurement. It is found that the T-c is improved (37.3-38.4 K) by subsequent Ar annealing treatment under various sintering temperatures and times. Remarkably, the annealed samples show significant improvement in the overall quality of the samples. On annealing at 1323 K for 0.6 ks, we obtained the best quality sample with a J(c) of 470 A mm(-2) at 2.0 T. In order to find out the irreversible field (B-irr), the technique of the Kramer plot was applied. The B-irr obtained was 7.6 and 9.6 T, for the as-rolled as well as the annealed samples at 1073 K for 3.6 ks, respectively. The mechanical properties were measured under tensile load. The yield stress was 450 MPa for the as-rolled sample and decreased by annealing at 1323 K for 0.6 ks to 110 MPa. After the wires were heat treated at temperatures between 1073 and 1323 K and tensile-stressed up to their yield stress at room temperature. The critical current measurements were carried on such samples at 4.2 K under applied magnetic fields of 2 and 5 T. The stress level for the 95% tolerance of critical current was determined to 97 MPa.
- リンク情報
- ID情報
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- DOI : 10.1088/0953-2048/16/9/315
- ISSN : 0953-2048
- Web of Science ID : WOS:000185770200016