Fabrication and properties of high j_c multifilamentary (bi,pb)-2223 tapes with ag-alloy sheath

(Bi,Pb)-2223 tapes with 37 filaments have been fabricated by powder in tube (PIT) method. Silver was used for the sheath of filaments and the Ag-Mn-Ni alloy was used for the outer sheath of the tapes. A high critical current density of 29000A/cm² (77K, 0T) has been achieved in rolled tape with Ag-alloy sheath, in this case the critical current of the tapes is 81.SA, which is higher than that of multifilainentary tapes with pure Ag sheath prepared by the same process. The precursor powders prepared by mixing the (Bi,Pb)-2212 and CaCuCO₂ has been considered to be beneficial for fabricating high J_c multifilamentary tapes with Ag-alloy sheath. The superconducting properties and microstructural characteristics of the multifilamentary tapes have been investigated in this work.