Title :
Current characteristics and microstructure in a multifilamentary Nb-37Ti-22Ta superconductor
Author :
Chernyi, Oleg V. ; Storozhilov, Gennadiy E. ; Ilicheva, Vera O. ; Starodubov, Yakov D. ; Lazareva, Marina B. ; Andrievskaya, Natalya F.
Author_Institution :
Kharkov Inst. of Phys. & Technol., Ukraine
fDate :
3/1/2001 12:00:00 AM
Abstract :
The 210-filamentary superconductor based on Nb-37Ti-22Ta, wt.% alloy was obtained by using the electric arc melting and deformation processing. During alloy drawing we used four isochronal intermediate heat treatments at the temperature 425°C. The total heat treatment duration was varied from 50 to 1000 hours. The true plastic strain value between heat treatments was 0.4 and after the final treatment was 3-5. The kinetics of phase transformation in the ternary alloy was investigated by the method of transmission electron microscopy. The J c value increases with an increasing quantity of the precipitated alpha-phase in medium magnetic fields. The Jc (5 T, 4.2 K) value reaches 3000 A/mm2 or more. In high fields, J c(10.4 T, 2.05 K) for the given superconductor was equal to 1600 A/mm2. The parameters responsible for the shape of pinning force curve are determined for different treatment conditions
Keywords :
critical current density (superconductivity); crystal microstructure; drawing (mechanical); flux pinning; heat treatment; melt texturing; multifilamentary superconductors; niobium alloys; plastic deformation; precipitation; superconducting tapes; tantalum alloys; titanium alloys; transmission electron microscopy; type II superconductors; 10.4 T; 2.05 K; 210-filamentary superconductor; 4.2 K; 425 C; 5 T; 50 to 1000 h; Jc; NbTiTa; alloy drawing; current characteristics; deformation processing; electric arc melting; heat treatment duration; isochronal intermediate heat treatments; microstructure; multifilamentary Nb-Ti-Ta superconductor; phase transformation; pinning force curve; plastic strain; precipitated alpha-phase; ternary alloy; transmission electron microscopy; Capacitive sensors; Heat treatment; Kinetic theory; Magnetic fields; Microstructure; Multifilamentary superconductors; Plastics; Superconducting materials; Temperature; Transmission electron microscopy;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
