Critical current density and n-value of NbTi wires at low field

Author

Inoue, Y. ; Kurahashi, H. ; Fukumoto, Y. ; Shimada, M.

Author_Institution

Electron. Res. Lab., Kobe Steel Ltd., Japan

Volume

5

Issue

2

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

1201

Lastpage

1204

Abstract

The manufacturing process of NbTi wires for lower field applications is optimized concerning both the number of heat treatments and the final true strain, the strain of a wire from the wire diameter at the last heat treatment to the final diameter. The sample wires were made from Nb 54wt%Ti alloy and were manufactured to vary the number of heat treatments (0, 1, 2, and 3) and the final true strain (0 to 3). One of these samples, which had one heat treatment and drew with the final true strain of 0.33, achieved J/sub c/ of 3360 A/mm/sup 2/ and n-value of 111 at 3 T. This J/sub c/ is as good as a J/sub c/ of the wires made from conventional materials and this n-value is 3 times as large as the n-value of wires mentioned above. Furthermore, the n-value at 3 T and the minimum value of the cross-sectional area of each filament show a correlation coefficient of 0.73.<>

Keywords

critical current density (superconductivity); heat treatment; internal stresses; multifilamentary superconductors; niobium alloys; titanium alloys; 3 tesla; NbTi; NbTi wires; correlation coefficient; critical current density; filament cross-sectional area; heat treatments; low field; manufacturing process; multifilamentary superconductor; n-value; strain; Capacitive sensors; Critical current; Critical current density; Heat treatment; Niobium compounds; Production; Titanium alloys; Titanium compounds; Voltage; Wires;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.402777

Filename

402777