高2223相含量粉末扩散连接BSCCO带材

Diffusion bonding using powders with a high-content of 2223 phase for superconducting Bi-based tapes

采用压制和高温烧结工艺获得了2223相含量达88.5%的粉末中间层,压制工艺有利于提高粉末中2223相的含量.用上述粉末实现了61芯BSCCO带材的超导扩散连接.结果表明,当连接温度为800℃、保温时间为2h及压力为3MPa时,接头平均超导连接效率CCRo可到达49.9%;粉末中2223相含量增加,接头连接效率提高.连接参数对接头显微组织的影响既明显又复杂.

A powder interlayer with a content 88.5% of superconducting phase 2223 was obtained by combining pressing technology and high temperature sintering from the precursor powders used for fabricating BSCCO tapes.The pressing technology is beneficial to increasing the formation and content of 2223 phase from the precursor powders.A good superconducting bonding quality was achieved using this powder interlayer.The average critical current ratio(CCRo)reached up to 49.9% under the conditions of bonding temperature 800 ℃ for 2 h at 3 MPa.And it is concluded that the higher the content of 2223 phase in the powder interlayer,the higher the CCRo is.The influences of bonding factors on the joints' microstructures are both obvious and complex,and a further research on this is needed.