Processing, microstructure and critical current density of 2223 BPSCCO/Ag tapes

Progress has been made in the development of long 2233 phase multifilamentary wire tapes using the powder-in-tube technique. Ramless extrusion was successfully used to deform multifilamentary precursor/Ag-composites of large diameter. After extrusion and wire drawing the mean variation coefficient of filament cross sections along the wire length was determined to be about 10%. Studies of 2223 phase formation in the wire cores have shown, that the conversion of the precursor to 2223 has been accelerated by annealing under reduced O/sub 2/ pressure compared with air. Critical current densities of 12 kA/cm/sup 2/ and about 5 kA/cm/sup 2/ (77 K; 0 T) were achieved for the 19 filament wire tapes of 17 m and 100 m length, respectively. J/sub c/ of tapes of 0.12 mm thickness has been suppressed around a strain value of 0.1%.<>