BSCCO-2223 tapes have been produced by the 'powder-in-tube' method with reproducible critical current densities of > 1 x 104 A cm-2 at 77 K and 5 x 104 A cm-2 at 4.2 K. Superconductivity at 77 K was retained in fields of up to 7 T. The influence of mechanical treatments (e.g. drawing, rolling and pr
Influence of partial oxygen pressure on the processing of Ag-sheathed BSCCO-2223 tapes
β Scribed by M. Penny; S. Feltham; C. Beduz; Y. Yang; R. Scurlock; R. Wroe
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 406 KB
- Volume
- 37
- Category
- Article
- ISSN
- 0011-2275
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β¦ Synopsis
The effect of sintering in various oxygen atmospheres on transport .I, has been investigated. The results of the peak J, with total sintering time are presented for each partial oxygen pressure ( PO2 = 0.04, 0.075, 0.21). Two important processing parameters of tapes were adjusted to ensure a fair comparison of each Po2. Firstly, as the melting temperature of BSCCO decreases with decreasing PO,, it was necessary to alter the sintering temperatures to maintain the same subcoolIng for each PO*. Secondly, the first and second intermediate rollings of the tapes were performed when there were equal amounts of 2223 phase. The peaks in J, against total sintering time occurred at 200 h for PO2 = 0.21, 45 h for PO,.= 0.075, and 90 h for PO2 = 0.04. This relates to the stability range and the incubation time of BSCCO-2223 in PO2 and could be an important tool to reduce the long processing time of optimized tapes.
π SIMILAR VOLUMES
Silver-sheathed tapes were fabricated using a Bi-2223 system. The tapes were processed to their final thickness by direct rolling as well as by repeated rolling with intermediate heat treatment. The rolling reduction rate was also varied to find its effect on the final properties. The critical curre