1996 年 31 巻 12 号 p. 653-659
The mechanical properties and the axial tensile strain and transverse compressive stress dependence of the critical current (Ic) in mono-core and 19 core Bi(2212) superconducting tapes with different sheaths were evaluated at a temperature of 4.2K and a magnetic field of 14T. Replacement of the Ag sheath with an Ag-Zr alloy sheath increased the 0.2% proof stress and the tensile strain for Ic degradation onset although Ic decreased markedly. A two-layer sheath with an Ag inner layer and Ag-Zr alloy outer layer improved both the stress-strain and strain characteristics of Ic without remarkable degradation of the Ic. Increasing the number of cores from 1 to 19 degraded the tensile strain vs. Ic characteristics of the tape, although no marked change in the critical current density was observed. The alloying of the sheath also improved the transverse compressive stress vs. Ic characteristics. The effects of Zr alloying of the Ag sheath on the mechanical behavior and stress/strain dependence of the Ic of superconducting composites are briefly discussed with emphasis on texturing of oxide superconductors.