Title :
Fabrication of Ag-sheathed Bi-superconducting tapes and coils
Author :
Liu, H.K. ; Ionescu, M. ; Guo, Y.C. ; Bhasale, R. ; Hu, Q.Y. ; Dou, S.X. ; Savvides, N. ; Apperley, M. ; Secrett, G. ; Collings, E.W.
Author_Institution :
Centre for Supercond. & Electron. Mater., Wollongong Univ., NSW, Australia
fDate :
6/1/1995 12:00:00 AM
Abstract :
Ag-clad (Bi,Pb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10+z/(2223) multifilament tapes up to 46 meters have been fabricated using powder-in-tube technique. A I/sub c/ of 15 A at 77 K over the entire length has been achieved with a fluctuation along the length less than 10%. Coils up to 306 turns with a I/sub c/ of 45.6 A at 4.2 K were produced through reaction and winding procedure using multifilament tapes. J/sub c/ versus phase formation, degree of texture and grain growth of Ag-sheathed Bi-based superconducting tapes have been investigated during thermomechanical processes. The initial modest increase in J/sub c/ is attributable to the increase of 2223 phase and grain alignment, while in second stage grain growth is mainly responsible for a rapid increase of J/sub c/. Prolonged annealing in the third stage results in recrystallisation of the large grains, and hence a decrease in J/sub c/. A I/sub c/ of 8 A at 77 K and 67 A at 4 K and zero field has been achieved for Ag-clad Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8+z/(2212) tape using a partial melting and atmosphere-controlled process.<>
Keywords :
annealing; bismuth compounds; calcium compounds; critical current density (superconductivity); grain growth; high-temperature superconductors; lead compounds; multifilamentary superconductors; powder technology; recrystallisation annealing; silver; strontium compounds; superconducting coils; superconducting tapes; texture; thermomechanical treatment; (Bi,Pb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10+z/; (BiPb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10/-Ag; 15 A; 2212 phase; 2223 phase; 4 K; 4.2 K; 45.6 A; 67 A; 77 K; 8 A; Ag-sheathed Bi-superconducting tapes; annealing; atmosphere-controlled process; critical current density; fabrication; fluctuation; grain alignment; grain growth; multifilament tapes; partial melting; phase formation; powder-in-tube technique; reaction and winding; recrystallisation; superconducting coils; texture; thermomechanical processes; Annealing; Australia; Fabrication; Multifilamentary superconductors; Powders; Superconducting cables; Superconducting coils; Superconducting filaments and wires; Superconducting films; Superconducting materials;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
