The effect of thermal cycling and axial strain on the IC degradation of multi-filamentary Bi-2223/Ag tapes

The effects of axial strain and thermal cycling on the critical current were investigated for the Bi-2223/Ag PIT tapes. The axial strain was applied to the tapes by the U-shape sample holder. Two kinds of Bi-2223/Ag tapes with different Ag sheaths were used to study the effect of sheath alloying on the tensile strain tolerance of the tapes. The influence of thermal cycling between room temperature and 77 K on characteristics was examined. Critical current was drastically decreased for Ag/alloy and Ag/alloy/alloy sheathed tapes by tensile strain above 0.22% and 0.3%, respectively. Thermal cycling did not affect the critical current of superconducting tape, but gradually degraded the critical current of the pre-strained tape.