Effects of compressive stress on the critical current of Bi-2223 tapes

We measured the critical current of Bi-2223 tapes as a function of transverse compressive stress perpendicular to the tape surface and side compressive stress parallel to the tape surface at 77K. The effects of the cross-section size on the stress characteristics of AgMn-alloy sheathed Bi-2223 tapes were compared. The onset compressive stress for degradation of Ic was lower in the thinner tape with a thin Ag sheath due to the stress concentration on the irregular interface. The irreversible transverse compressive stress and side compressive stress of the tapes with AgMn-alloy sheath were usually higher than 100MPa, which essentially meet the requirements of technical application.