HTS电流引线中接头电阻的研究和焊接工艺

Study on joint resistances and solder technique for HTS current leads

针对Bi-2223/Ag-Au高温超导带材制造的二元HTS电流引线设计中不同材料之间连接的技术要求,设计了减小接头电阻的焊接工艺实验,包括焊接温度、焊料、搭接长度和焊锡层厚度对接头电阻的影响。着重分析了HTS电流引线中应用的三种接头的焊接工艺对焊接电阻的影响,并总结出在HTS电流引线中接头电阻的焊接工艺参数。

Three different types of joining between Cu and Cu, Cu and HTS, HTS and HTS were prepared and current - voltage characteristic curves were investigated at 77K. SpeeifieaUy,a kind of solder was tested. Contact resistances of joint parts was estimated from curves. The resistance values of three different types of joining were calculated to be 10^-7～10^-8Ω magnitude in liquid nitrogen temperature. The best soldemg process was designed,too. In curves of samples joined with HTS tapes, it was found that joint resistance depends on variation of overlapped -length. From consideration of Joule beat generation, such joining method is available for fabricating HTS current leads.