Bending properties of solder joint of YBCO coated conductors by etching copper stabilizer

The YBa2Cu3O7-x coated conductor (YBCO CC) is one of the most promising superconducting materials for magnet applications because of its high critical current (I-c) and low dependency of the I-c on the external magnetic field. For magnet applications, plenty of joints are required to meet the connection of relatively short YBCO CC tapes. The bending properties of the joints inevitably become one of the critical factors that determine the performance of the superconducting magnet. In this paper, we fabricated the joints of YBCO CC tapes by etching Cu stabilizer and studied their bending properties under various bending diameter at 77 K and self-field. Compared with the soldering joint, lower joint resistance (R-j) and preferable electrical properties under applying various bending deformation were achieved and proved by the bending strain tests and finite element simulations. This fabrication technique is a unique practicable solution to reduce the R-j and improve the bending properties for the joints of YBCO CC tapes with thicker metal stabilizing layers in second generation high temperature superconductor (2G HTS) applications.