1995 年 30 巻 3 号 p. 150-153
The mechanical properties and the axial tensile strain/transverse compressive stress dependence of the critical current, Ic, in Ag sheathed Bi (2212) 7-core superconducting wires with different construction were evaluated at a temperature of 4.2K and a magnetic field of 14T. Increase of the superconductor volume fraction shifted the stress-strain curves upward. The tensile strain for Ic degradation onset was in the range of 0.14-0.27%. It depended on the residual compressive strain and the thickness of the superconductor layer. On the other hand, the transverse compressive stress for Ic degradation onset was in the range of 9-20MPa. The wires with thin Ag sheath layer showed a remarkably large degradation in the onset stress. There was no correlation between the onset stress for degradation of Ic caused by the tensile stress and that caused by the transverse compressive stress.