THE EFFECT OF CRYOGENIC DEFORMATION ON Bi2223 SUPERCONDUCTING TAPES

The effect of the cryogenic deformation on the Bi2223 superconducting tapes has been investigated in this paper. Mechanical deformation was carried out on the Ag-sheathed mono- and multi- filamentary Bi2223 and silver alloy-sheathed multi-filamentary Bi223 tapes at liquid nitrogen temperature (77K) and room temperature separately. Result shows that the critical current of the Bi2223 tapes is significantly enhanced by cryogenic deformation. The SEM microstructure observation shows that the cryogenic-tapes have higher core density, smoother silver/superconductor interface and better grain alignment. The tensile test shows that the tapes pressed at liquid nitrogen temperature have better tensile behavior than tapes pressed at room temperature.