摘要
铁基超导材料在高场超导磁体领域具有很大的应用潜力,而研究具有高传输临界电流密度的多芯复合包套线材对于其实际应用至关重要.本研究基于粉末装管法,结合孔型轧制工艺和热等静压烧结工艺制备了多芯Cu/Ag复合包套(Ba,K)Fe_(2)As_(2)(Ba-122)超导线材.通过对不同直径线材中Ba-122超导芯的质量密度、晶粒取向、晶粒尺寸、元素分布与线材的电流传输性能之间的关系进行系统研究,我们发现线径较小的样品中超导晶粒间的耦合得到了显著增强,其传输临界电流密度在4.2 K,10 T下达到3.3×10^(4)A cm^(-2),同时由于晶粒尺寸和超导芯丝的均匀性得到改善,其电流传输的一致性(n值)也获得有效提高.本研究为制备高性能、高度均匀的铁基超导多芯线材提供了一种可规模化的工艺路线,对促进铁基超导材料的高场强电应用有重要意义.
Iron-based superconductors(IBSs)show great promise as materials for high-field magnets.Developing multi-filamentary wires with a large critical current density(J_(c))and high mechanical strength is essential for high-field applications.In this work,multi-filamentary Cu/Ag compo-site sheathed(Ba,K)Fe_(2)As_(2)(Ba-122)wires with various dia-meters were prepared using an ex-situ powder-in-tube(PIT)method and heat-treated by a hot isostatic pressing(HIP)process.Notably,the transport J_(c) of these wires,prepared by groove rolling,generally increases as the diameter decreases from 2.0 to 1.0 mm and reaches a maximum J_(c) of 3.3×10^(4) A cm^(-2)(4.2 K,10 T)in wires with a diameter of 1.0 mm.Additionally,the n-value of the transport J_(c) was greatly in-creased in the 1.0-mm-diameter wire.We systematically in-vestigated the relationship between these improved transport properties and the evolution of mass density,grain alignment,and element distribution in Ba-122 filaments of wires with different diameters.Our work proves that higher mass density and improved grain texture through the groove rolling process are beneficial for improving the transport J_(c).Furthermore,our results show the possibility of cost-effective and scalable ap-plications of(Ba,K)Fe_(2)As_(2) multi-filamentary wires,which,due to their unique structure,are set to become the most pro-mising competitors for high-field applications.
作者
郭文文
姚超
熊颢
杨鹏
涂畅
马衍伟
Wenwen Guo;Chao Yao;Hao Xiong;Peng Yang;Chang Tu;Yanwei Ma(Key Laboratory of Applied Superconductivity,Institute of Electrical Engineering,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China;Institute of Electrical Engineering and Advanced Electromagnetic Drive Technology,Qilu Zhongke,Jinan 250013,China;School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,China)
基金
partially supported by the National Key R&D Program of China (2018YFA0704200)
the National Natural Science Foundation of China (51977204,52107031,and 51721005)
the Strategic Priority Research Program of Chinese Academy of Sciences (XDB25000000)
the International Partnership Program of Chinese Academy of Sciences (182111KYSB20160014)。
