High critical current YBa₂Cu₃O₇artificial joints using Ag foils as welding agent

Abstract

A new high quality joining technique of melt processed YBCO has been developed based on interfacial melting induced by a metallic silver foil inserted between two single domain YBCO tiles. This simple technique allows joining large monoliths to form the complex-shaped pieces required for many power applications. Hall probe magnetic flux profile analysis under magnetic field and high field magnetoresistance measurements demonstrate that the superconducting behaviour of the joint is indistinguishable from the bulk.

Critical State of YBCO Superconductors With Artificially Patterned Holes

“…This system has been already widely tested in the characterization of other sorts of YBCO samples, like bulk cylinders [11], rings [12], YBCO/Ag/YBCO welds [13], [14] and YBCO foams [7]. Fig.…”

Fast joining of melt textured Y–Ba–Cu–O bulks with high quality

“…Iida et al [13][14][15] have fabricated Ag-doped Y-Ba-Cu-O (Ag 2 O additive) sintered plates as solder to join the Y-Ba-Cu-O bulks and obtained high quality joint with uniform trapped-field distribution. Harnois et al [10] also got similar result by using Ag-doped Y123 mixture (Ag additive) as solder. There was a slight difference between these two joining materials: Iida et al used (Y123 + 25 wt.% Y211) + 10 wt.% Ag 2 O, while Harnois et al used (Y123 + 5% mol Y211) + 5 wt.% Ag + 0.5 wt.% CeO 2 .…”

“…Most of them joined two Y-Ba-Cu-O bulks by self-seeded methods. Noudem et al [7] used dispersed Yb123 powder in glycerin as solder; Iliescu et al [8][9][10][11] and Bozzo et al [12] have developed Y-Ba-Cu-O/Ag/ Y-Ba-Cu-O structure to realize joining, and the results of these experiments were very encouraging. Iida et al [13][14][15] have fabricated Ag-doped Y-Ba-Cu-O (Ag 2 O additive) sintered plates as solder to join the Y-Ba-Cu-O bulks and obtained high quality joint with uniform trapped-field distribution.…”

A superconducting joint for GdBa2Cu3O7−δ-coated conductors

“…[6][7][8] Unfortunately, these CCs have not been used in superconducting devices with persistent current mode (PCM) operation such as magnets for magnetic resonance applications owing to the unavailability of fabrication techniques for proper joining and contacts. [9][10][11][12] An ideal joint for 2G high-temperature superconducting (HTS) CCs requires perfect physical, chemical and mechanical continuity and uniformity throughout the CC-joint-CC connection, as well as sufficient metallurgical capacity without the formation of deleterious constituents, mechanical soundness and good performance under varying conditions, including closed-loop conditions for PCM operation. Various joining methods such as soldering are unsuitable for such joints because of their high joint resistance (20-2800 nO).…”