Title :
Dynamic heat treatment of BSCCO-2212 tapes with homogeneous properties and high critical current density
Author :
Flahaut, E. ; Bourgault, D. ; Bruzek, C.E. ; Rikel, M.O. ; Herrmann, P. ; Soubeyroux, J.L. ; Tournier, R.
Author_Institution :
CRETA/Lab. de cristallographie, Grenoble, France
fDate :
6/1/2003 12:00:00 AM
Abstract :
Melt-processed Bi2Sr2Ca1Cu2O8+x/Ag tapes are now commercially available in long lengths. The melting step, which is mostly important for tape performance is difficult to control on the industrial scale. A dynamic approach is proposed. The melting step and subsequent annealing (2212-formation) step are separated. For the melting step, the reel-to-reel transfer system through a 140-cm long furnace was developed. The maximum processing temperature in the hot zone can be controlled to within 1°C; heating rate from 3000°C/h to 30000°C/h and cooling rate between 60°C/h to 30000°C/h. The effect of heat treatment parameters characterizing the melting step on the transport critical current densities at 4.2 K was studied and correlated to microstructure characterized by SEM/EDS and X-ray diffraction analyzes.
Keywords :
X-ray diffraction; annealing; bismuth compounds; calcium compounds; critical current density (superconductivity); heat treatment; high-temperature superconductors; scanning electron microscopy; silver; strontium compounds; superconducting tapes; 140 cm; 4.2 K; BSCCO-2212 tapes; Bi2Sr2Ca1Cu2O8+X/Ag tapes; Bi2Sr2Ca1Cu2O8+x-Ag; SEM/EDS; X-ray diffraction; annealing; dynamic heat treatment; high critical current density; high temperature superconductor; homogeneous properties; hot zone; maximum processing temperature; melt-processed; melting step; microstructure; reel-to-reel transfer system; Annealing; Bismuth; Critical current density; Electrical equipment industry; Furnaces; Heat treatment; Heating; Industrial control; Strontium; Temperature control;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2003.812065
