Thermal Analysis of Sonic-Welding Process and Investigation of Process-Induced Degradation in Superconducting Properties
世良 真也, WU Zeyu, 東川 甲平, 木須 隆暢 (九大)
Abstract:For practical use of REBCO CCs, a robust low-resistive joint technique is essential. Sonic welding enables rapid low-resistivity joints. We developed a solder-free sonic welding process and achieved reproducible low-resistivity joints. However, degradation of critical current can be induced under some conditions. We performed finite element thermal analysis of the sonic-welding process and examined conditions causing degradation. We identified a maximum-temperature threshold that can induce Ic degradation and clarified conditions enabling low resistivity without Ic degradation.