Critical Current and Strain Tolerance of Bi-2223/Ag Multifilament Tapes

Damage evolution under bending and tensile stress and its influence on critical current of Bi2223/Ag superconducting composite tape

“…The strain-dependence of critical current is dependent on the fabrication process and structure of the composite such as size and volume fraction of the constituents (Bi2223, silver and silver alloy sheath), as known from the comparison of the reported results [1][2][3][8][9][10][11][12][13][14][15][16]. Taking the case of the bending effect, the reduction in critical current with increasing strain has been attributed mostly to the damage in the tensile side.…”

“…The tensile fracture strain of the Bi2223 filaments has been reported to be around 0.1% [2][3][4], being several to ten times lower than that of other superconducting filaments such as Nb 3 Sn (0.5-1.2%) [5,6] and Nb 3 Al (0.6-1.0%) for fusion uses [7]. Thus, under the applied strain, the critical current of Bi2223 composite is reduced severely [1][2][3][8][9][10][11][12][13][14][15][16].…”

A Monte Carlo–shear lag simulation of tensile fracture behaviour of Bi2223 filament

“…Thus the understanding of the fracture behaviour of the Bi2223 tape under applied strain ε c and its influence on critical I c is an important research subject. On this subject, several investigations have reported the following: (1) in well-textured Bi2223/Ag/Agalloy composite tapes fabricated by powder-in-tube methods, the Bi2223 grains are aligned with their c-planes (often referred to as the a-b plane) approximately parallel to the tape longitudinal direction [17][18][19]; (2) the critical current I c remains nearly the same as the original one at low applied strains but is reduced at high strains due to the damage of the filaments [3][4][5][6][7][8][9][20][21][22][23][24][25][26][27][28][29][30][31]. The critical current I c -strain relation is reversible when the applied strain ε c is lower than a critical value ε irr but it becomes irreversible when the applied strain exceeds ε irr .…”

Microscopic fracture of filaments and its relation to the critical current under bending deformation in (Bi,Pb)2Sr2Ca2Cu3O10composite superconducting tapes

“…Although there have been detailed analyses on the stress and strain states of each component for Bi2223 tapes in tension [1,7], they have mainly dealt with only two-phase Bi2223/Ag tapes. For the case of bending deformation, Savvides and co-workers have carried out pioneering experimental researches [3,14,15] including cyclic straining effects [14] and microscopic damage observations [15]. These works were followed by a few studies dealing with the analysis of the microscopic stress and strain states of each component.…”