Tensile strain transverse compressive stress dependence of critical current in Bi(2212) superconducting tapes with Zr-reinforced Ag sheath

The tensile mechanical property and the axial tensile strain/transverse compressive stress dependence of the critical current I-c in mono-and 19-core Bi(2212) superconducting tapes with Zr-reinforced Ag sheaths were evaluated at a temperature of 4.2 K and a magnetic field of 14 T. Replacement of Ag sheath by Ag-Zr alloy sheath increased the 0.2% proof stress and the onset tensile strain for I-c degradation although I-c decreased markedly. Double layer sheath with Ag inner layer and Ag-Zr alloy outer layer improved both the stress-strain relation and the strain characteristics of I-c without remarkable degradation in I-c. The increase in the number of core from 1-19 degraded the tensile strain vs. I-c characteristics of the tape, although no marked change in critical current density is observed. The alloying of sheath also improved the transverse compressive stress vs. I-c characteristics. The effects of Zr alloying of Ag sheath on the mechanical behavior and the stress/strain dependence of I-c of the superconducting composites are briefly discussed with emphasis on texturing of the oxide superconductor. Published by Elsevier Science Ltd. All rights reserved.