Comparative tensile strain analysis on Bi-2223 composite superconducting tapes

Comparative tensile strain analysis has been reported on the commercially available Bi-2223 composite superconducting tapes. Five multifilamentary tapes used in this study were obtained from five different manufacturers. The analysis for comparison is based on (i) the change in engineering parameters such as yield strength and elastic modulus at room temperature (RT), and at 77 K, (ii) the strain tolerance and degree of degradation of the critical current (Ic) for each tape at 77 K. The experimental data were qualitatively discussed on the bases of the rule of mixture to estimate the fracture strain of the oxide filaments from the stress-strain curve and its relation to the stress-strain behaviour for all relevant materials composed into the Bi-2223 superconducting tape is evaluated.