Powder-metallurgy-processed Nb//3Al wires with low areal production ratios of R equals 8 multiplied by 10**3 to 1 multiplied by 10**4 have been investigated as to their superconducting properties. High-field J//c values for Nb-8 wt% Al with different areal reduction ratios were optimized. T//c was 17. 1 K for the sample with a two-stage heat treatment, such as 1200 degree C for 15 sec followed by 750 degree C for three days. This was in contrast to the low T//c values (below 16 K) for the samples with a single heat treatment at 800 degree C. B//c//2 for a two-stage heat-treated sample increased about 5 T at 4. 2 K in comparison with a single heat-treated sample. The measured B//c//2 values were well fitted to the theoretical curve of the upper critical field. The overall J//c values were measured up to 23 T at 4. 2 K, and J//c equals 10**4 A/cm**2 at 17. 5 T was achieved.
|Journal||IEEE Transactions on Magnetics|
|Publication status||Published - 1987 Jan 1|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering