Effect of sheath material on structure and properties of BPSCCO-2223 conductors

In order to improve the mechanical properties of BPSCCO conductors two alternative methods of hardened sheaths processing were proposed: the fabrication of starting tube from silver alloy with Y and Ni additions in amount less than 0.2 wt. % (Ag-Ni-Y) or from the powder mixture of the same components. Investigation of the mechanical properties of tapes 0.15x4.2 mm2 in section reveals increase of tensile strength after annealing at 840 °C for 200 h by a factor of 3 in comparison with relevant values for Bi-2223/alloy sheathed tapes in the interval between 77 K and 293 K.