Diffusion bonding of superconducting Nb-59.8 at % Ti plates

The applicability of diffusion bonding to superconducting joints is examined using a joint between two Nb-Ti plates. The joint made at 9000C yields critical current density nearly equal to that of base metal by post-bond treatment, i.e., cold-rolling plus aging process. The reduction in critical temperature of as-bonded joint was within 1 K at all the bonding temperatures (600 - 9000C). The ultimate tensile strength of the joint made at 9000C reached that of base metal, but the breaking strain was reduced. The diffusion bonding is likely to be applied to joining superconducting Nb-Ti plates with an appropriate post-bond process. (author)