Joining of REBCO Coated Conductor Tapes Using Ultrasonic Welding Method

In coil manufacturing for magnets and other electrical device applications that require long lengths of tapes, the joining of coated conductor (CC) tapes is still necessary. The joint is a critical part that may affect the performance of a particular device during its operation. Thus, a practical joint method which has a strong adhesion and low contact resistance without critical current I_c degradation should be developed to meet both purposes of electrical and mechanical connections. In this study, a new joint method using ultrasonic welding (UW) was introduced and the parametric tests were performed to produce a good quality of UW joint. The mechanical-controlled solder joint method was also adopted for comparison. The electrical properties such as I_c and specific joint resistance R_sj were measured at 77 K and the results were compared for each method.