Fabrication and performance studies of the soldering joint for Ba122 iron-based superconducting tape
This paper focused on the fabrication process of Ba122 iron-based superconducting strips with soldering joints,using different solders to fabricate iron-based superconducting soldering overlap and bridged joints and investigating their per-formance.The performance tests of the joint samples were carried out to obtain the resistance value of the joints at 4.2 K.The mechanical strength of the joints was also evaluated.The results show that,for lap joints,the use of high melting point solder sig-nificantly reduces the joint resistance to a minimum of 45 nΩ,while for bridge joints,considering the properties of the intermedi-ate superconductor YBCO,the use of low melting point solder is recommended,with a minimum resistance of 108 nΩ.The joint resistance decreases with the increase of the length of the joints,but excessively long joints lead to an increase in the deviation of the theoretical from the actual resistance values.In addition,different solders have little effect on the mechanical strength of the joints,and the strength is mainly dependent on the superconducting strip itself.The mechanical strength of heat-treated iron-based strips and joints is not high,so special protection is required when fabricating iron-based superconducting coils.
NETL
NSTL
万方数据
