Jointing of Coated Conductors by Using Nano-particle Metal Pastes

Publication date: 2016 Source:Physics Procedia, Volume 81 Author(s): Tsuyoshi Nakanishi, Takato Machi, Teruo Izumi, Ryo Teranishi, Tomohiro Kato, Takeharu Kato, Tsukasa Hirayama Development of a jointing technique of coated conductors is important for all applications, such as superconducting magnets, cables, etc. Low resistance jointing techniques by means of silver diffusion [1] and for superconducting joints[2] have been reported so far. Since these processes were carried out at higher temperatures than the O2 annealing temperature for appropriate carrier doping to the REBa2Cu3O7-d (REBCO) crystals and resulted in oxygen deficiency in the REBCO crystals, long time O2 annealing was required for compensation of this oxygen deficiency. Because the long time and high temperature post annealing is an inappropriate process as on-site technology, solder jointing technology has been widely accepted, in general, for practical applications. However, the resistance of the solder joint is 50 - 100 nΩ, and then the Joule heat generation in the joint region is a serious problem and must be solved. Consequently, we have studied a new jointing technique by using the pastes containing of silver or gold nano-particles. Because the I c value of GdBCO was deteriorated with higher temperature heat treatment, we have tried to develop a jointing technology with the low temperature (below 200°C). We used the nano-particle metal pastes (∼5nm) which contained dispersants aroun...
Source: Physics Procedia - Category: Physics Source Type: research