Presentation Information
[23a-12N-8]Low Resistance Joining of REBCO Coated Conductors with Metal Stabilization Layers by Sonic Bonding Process
〇Shinya Sera1, Yusuke Oda1, Kenji Suzuki1, Zeyu Wu1, Kohei Higashikawa1, Takanobu Kiss1 (1.Kyushu Univ.)
Keywords:
Superconductivity,REBCO wire,Sound bonding process
Regarding the joining of REBCO-coated wires with metal stabilized layers, we have succeeded in joining the interface of the metal stabilized layers with low resistance by applying sound vibration to the pressurized workpiece. In the conventional method, sufficient low resistance could not be obtained due to the existence of voids in the interface, and a hybrid method such as solder to fill the voids or insertion of an intermediate metal was indispensable. The joint resistivity was successfully obtained with good reproducibility to less than 20 nOhmcm2 , which is the lowest value ever achieved. In addition, by applying a technique to visualize local defects using magnetic microscopy, it was confirmed that a defect-free and healthy joining region was obtained, and it was also clarified that local degradation occurs when the peak power during the process exceeds a threshold value of ~600 W/cm2. In addition to Cu, the case of Ag as the top surface layer was also investigated.