Application of two-axial rolling for multicore Bi(2223)/Ag tapes

Abstract

Multicore Ag-sheathed Bi(2223) tapes have been prepared by OPIT technique using the two-axial rolling deformation by active `Turk's head' roller. In comparison to wire drawing, the presented technique allows one to avoid the tensile stress during composite deformation and to increase the BSCCO-core density. A better homogeneity of filaments has been obtained by two-axial rolling. The transport critical current and its angular dependencies have been measured for single and 36 filament rectangular wires and tapes. Total tape widening influences the transport current density considerably but anisotropy at 0.1 T and 77 K is affected only slightly. Reduced anisotropy has been measured in a single core wire which has texturing of grains in two perpendicular rolling planes.