高场磁体用Nb_3Al超导线材研究进展  

Research Progress of Nb_3Al Superconducting Wire for High-Field Application

作　　者：崔利军[1] 张平祥[1,2] 潘熙锋[1] 闫果[1] 齐铭[2,3] 王大友[1] 刘向宏[1] 冯勇[1] 白质明[3] 

机构地区：[1]西部超导材料科技股份有限公司超导材料制备国家工程实验室,陕西西安710018 [2]西北有色金属研究院,陕西西安710016 [3]东北大学,辽宁沈阳110004

出　　处：《中国材料进展》2015年第1期64-72,78,共9页Materials China

基　　金：国家磁约束核聚变能研究专项(ITER)资助项目(2011GB112001);国家自然科学基金(51302224)

摘　　要：Nb3Al超导体的超导转变温度(Tc)和上临界磁场(Hc2)与Nb3Sn类似,但具有更好的应力应变容许特性和高场临界电流密度(Jc)。因此,被认为是下一代高场磁体应用的理想材料。目前国际上报道的Nb3Al超导线材单根长度可以达到2.6 km;在4.2 K和15 T条件下,Jc达到1 000 A/mm2;但是由于制备工艺的复杂性,目前仍然无法实现大规模工业化应用。首先阐述了Nb3Al超导材料的基本特性,如Nb/Al扩散间距小、二者硬度匹配性小和低温热处理导致Al含量偏离化学计量比等,以及由此带来的材料加工和热处理方面的难点;系统介绍了近年来针对Nb3Al超导长线性能提升,在前驱体制备工艺、热处理工艺和表面覆Cu工艺方面的研究进展,并对不同的工艺进行了比较分析,重点讨论了线材制备过程中存在的关键性难点问题;最后,对Nb3Al超导材料的发展趋势进行了展望。The superconducting transition temperature （ Tc ） and upper critical magnetic field （ Hc2 ） of Nb3 Al superconductor are similar to Nb3 Sn, but it has better strain tolerance and higher critical current （ Jc ） at high field. Therefore, Nb3 Al superconductor is considered as a very appealing material for use in future high field application. At present, the Nb3 Al superconducting wire with 2. 6 km long length had been reported, which exhibited a large J, of 1 000 A/mmz at 4.2 K and 15 T. Due to the complexity of fabrication techniques, it can not be commercially applied. In this paper, the basic properties of Nb3 Al are introduced, such as little diffuse space, large difference in hardness and off-stoiehiometric with low temperature heat-treatment. Besides, various precursor fabrication, heat-treatment and Cu cladding techniques are described and compared, and the difficulties of fabrication, processes are analysed especially. In the end, a perspective and future development of Nb3 Al superconductor are given.

关 键 词：Nb3Al 超导线材 制备工艺 超导性能 高场磁体 

分 类 号：O511[理学—低温物理]