PROCESSING, MICROSTRUCTURE AND CRITICAL-CURRENT DENSITY OF 2223-BPSCCO AG TAPES/

Progress has been made in the development of long 2223 phase multifila mentary wire tapes using the powder-in-tube technique. Ramless extrusi on was successfully used to deform multifilamentary Precursor/Ag-compo sites of large diameter. After extrusion and wire drawing the mean var iation coefficient of filament cross sections along the wire length wa s determined to be about 10%. Studies of 2223 phase formation in the w ire cores have shown, that the conversion of the precursor to 2223 has been accelerated by annealing under reduced O-2 pressure compared wit h air Critical current densities of 12 kA/cm(2) and about 5 kA/cm(2) ( 77 K; 0 T) were achieved for the 19 filament wire tapes of 17 m and 10 0 m length, respectively. Jc of tapes of 0.12 mm thickness has been su ppressed around a strain value of 0.1%.