Bending Strain Effects on the Critical Current in Cu and Cu–Nb–Stabilized YBCO-Coated Conductor Tape

High strength and high electrical conductivity Cu-Nb tape was tested as the new type of stabilizing layer for YBCO-coated conductor. For electrical interconnection of stabilizing layer to coated conductor the soldering process was used and no degradation in critical current, I_c, of laminated coated conductor after soldering process was observed. The dependence of normalized transport critical current, I_c/I_c0, on the bending radius of coated conductors with and without Cu-Nb stabilizing layer was investigated using the bending test probe providing the uniform bend process at 77 K and under self-field conditions. The reversible and irreversible variations of I_c/I₀ with inverse bending radius were found and the irreversible bending radius limit was observed to depend on the neutral axis shift. The generation of the cracks appears to be the primary reason for the I_c/I_c0 degradation that was supported by ScanHall technique investigations.