Stress–strain behavior and degradation of critical current of Bi2223 composite tapes

Abstract

Stress–strain curve of commercially available Bi2223 multi-filamentary tapes was measured at RT and 77 K, which are composed of Bi2223, Ag and Ag alloy. The yielding at 77 K takes place at larger applied strain than that at RT. This behavior was discussed in terms of the residual strain during cooling. The reversibility of strain dependence of I c was investigated in detail in the low strain region. It recovered reversibly when the maximum strain was less than 0.33%. However, when the applied strain exceeded 0.38%, the irreversible behavior was clearly confirmed. This is the first result that the strain region of reversible change of I c exists in Bi2223 composite tape.