钇基和镱基钎料钎焊YBCO高温超导块材研究

Study on brazing of high temperature superconducting YBCO bulks with YBCO-based and YbBCO-based filler

采用YBCO基和YbBCO基两种超导钎料对YBCO高温超导块材进行了钎焊连接,测试比较了原始超导块材和经过氧恢复处理的钎焊接头的磁浮力,以评价块材和钎焊接头的超导性能,并对YBCO超导块材的钎缝组织进行了微观分析。结果表明,在本文工艺条件下,钎焊接头的磁浮力密度最高可达原母材的79.4%。采用钎焊连接技术可以实现高性能YBCO超导块材的大尺寸化。微观组织分析表明,钎缝区出现了Y211相或(Y,Yb)211相的富集,211相的富集对接头的超导电性有不利影响。

The brazing of high-temperature superconducting YBCO bulks was performed using YBCO-based and YbBCO-based brazing filler.The levitation force of the superconducting base bulks and the brazed joints after oxygenation was measured to evaluate the superconducting properties.The microstructure of YBCO base bulks and the brazed joints was also analyzed.The results indicated that the density of levitation force of the joints reached up to 79.4% of the original YBCO bulks under the technological conditions in this study.It was proved that brazing technology can be used to achieve the dimension-increment of superconducting YBCO bulks.Microstructure analysis shows that aggregation of Y211 or（Y,Yb） 211 appeared in the brazing seam and has negative effects on superconductivity of the joints.