Preparation of dispersion-hardened single- and multifilamentary Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub x/ tapes and wires

The impact of oxide dispersion-hardening on the mechanical behavior of powder-in-tube Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub x/ tapes is investigated. Single-core tapes and multifilamentary tapes with 19 filaments were prepared from commercially available AgMg tubes and powder. The cold-working process was monitored by observing sample microstructures at intermediate stages. The deformation process was optimized to eliminate bridging in the multifilamentary conductor. Short samples were heat-treated and characterized by critical current measurements (I/sub c/) at 4.2 K and 0 T. The maximum filament critical current density (J/sub c/) obtained was 115,000 A/cm/sup 2/ corresponding to an engineering critical current density (J/sub c/) of 22,000 A/cm/sup 2/.