An axial tensile stress was applied to 4 different composite wires containing NbTi, Nb3Sn, Bi-2223 and MgB2 at room temperature. The basic mechanical properties obtained from the stress-strain characteristics of these wires were compared. The wire samples were then tested by performing transport critical current measurements at 4.2 and 77K. The results showed that the critical current degradation of all of the composite wires occurred at the stress value which corresponded to the beginning of plastic deformation. The data had important implications for the technological application of such superconducting wires.

Tensile Stress Applied to NbTi, Nb3Sn, Bi-2223 and MgB2 Composite Superconductors at Room Temperature. I.Husek, P.Kovác, H.Jones: Superconductor Science and Technology, 2004, 17, 1411-4