Electromechanical Characterization of Bi-2212 Strands

The uniaxial strain dependence of critical current was measured both in tension and compression in Bi 2 Sr 2 CaCu 2 O 8+x (Bi-2212) high-temperature superconducting round wires. Permanent damage to the critical current easily occurred due to strain. To improve the electromechanical properties of Bi-2212 wires, development of stronger sheathing materials is needed. Ideal materials would be not only mechanically strong, but also chemically compatible with Bi-2212 during the final heat treatment. To identify such materials, we measured stress-strain properties of some new Ag alloys and extracted their respective Young's modulus values and yield strength. The database may be useful for development of new Bi-2212 strands for fabricating high-field superconducting magnets above 20 T.