Development of Bi-2223/Ag-alloy tapes

The reliable fabrication of robust, uniform, long length silver-sheathed Bi-2223 superconductor tapes capable of carrying high current densities represents a key factor towards the development of windings to be integrated in electric power devices. Bi-2223 tapes to be used for the fabrication of coils with silver alloy sheath having 19 and 55 filaments in unit length of 100 meters have been fabricated by the Powder In-Tube method, The critical current density enhancement of Bi-2223 tapes by means of the optimisation of mechanical deformation and thermal treatment parameters is here presented. The realised Bi-2223 tapes have been deeply characterised by DC and AC measurements at different temperatures. To evaluate the capabilities of the multifilamentary tapes in the realisation of coils their electrical behaviour as a function of magnetic field and bending strain has been investigated.