The development of argon arc brazing with Cu-based filler for ITER thermal anchor attachment

Thermal anchor is the key components of ITER magnet supports to maintain the low temperature for the normal operation of superconducting coils. During the advanced research of ITER thermal anchor attachment, dozens of brazing filler and several kinds of brazing technique have been developed and investigated. Argon arc brazing with Cu-based filler was chosen as the principal method for the attachment of thermal anchor. The brazing temperature of Cu-based filler is over 1000°C,but heat input is relatively low for shallower heating depth of argon arc brazing. Lower heat input is good for the control of brazing deformation. It is no need to clean after brazing because for argon arc brazing there is no brazing flux used. The test result shows that Cu-based alloy have the best mechanical properties at both room temperature and 77K for high brazing temperature. Detail of argon arc brazing with Cu-based filler have been investigated in this article.