Critical current of laminated and non-laminated BSCCO superconducting composite tape under bending strain

摘要

It has been reported that, when the (Bi, Pb)2Sr2Ca2Cu3Ox (hereafter noted as BSCCO)/Ag/Ag-alloy tape is laminated with stainless steel, the tensile strain tolerance of critical current is much improved. In this study, using the non-laminated and laminated BSCCO composite tapes fabricated at American Superconductor Corporation, the influences of lamination on the critical current and its distribution under bending strain were studied. The analysis of the measured variation of average critical current with bending strain based on the damage evolution model revealed that the laminated stainless steel acts to suppress the fracture of the BSCCO filaments. The experimentally observed high critical current retention of the laminated tape up to high bending strain was accounted for by the suppression of fracture of BSCCO filaments stated above and enhancement of the compressive residual strain in the filaments. The distributions of local critical current in non-laminated and laminated composite tape were described well by the three-parameter Weibull distribution function within the bending strain lower than 1.1%. The coefficient of variation of distribution of critical current of the laminated tape was similar to that of the non-laminated one under the same strain distribution in the core.