Manufacture, electromagnetic properties and microstructure of an 18-filament jelly-roll Nb3Al superconducting wire with rapid heating and quenching heat-treatment
Manufacture, electromagnetic properties and microstructure of an 18-filament jelly-roll Nb3Al superconducting wire with rapid heating and quenching heat-treatment
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DOI：
10.1088/0953-2048/29/1/015008
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发表时间：
2015
影响因子：
3.6
通讯作者：
X. F. Pan;Yijun Feng;G. Yan;L. Cui;Chuan Chen;Yong Zhang;Z. X. Wu;X. H. Liu;Ping Zhang-Ping-Zhan
中科院分区：
文献类型：
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作者：
X. F. Pan;Yijun Feng;G. Yan;L. Cui;Chuan Chen;Yong Zhang;Z. X. Wu;X. H. Liu;Ping Zhang-Ping-Zhan
本文报道了一种新型结构简单的双辊Nb 3Al前驱体长线材的制备，并对其电磁性能和组织进行了不同的快速加热和淬火（RHQ）热处理。通过对三种制备方法的比较，发现轧制拉拔法更适合于不经退火的超长Nb 3Al前驱线的制备。利用自制的RHQ设备，在不同的加热条件下，成功地对Nb_3Al线材试样进行了RHQ热处理。磁化强度和磁阻率测量结果表明，优化后的Nb 3Al丝的超导起始转变温度Tc和上临界场Hc 2（0）分别达到17.9K-18.0K和29.7T。通过显微结构和成分分析，优化线材中Nb 3Al超导体呈现典型的“层-层”结构，由晶态Nb 3Al和非晶态Nb层交替组成，Nb 3Al晶粒尺寸约为100 nm ~ 300 nm。此外，由于Al向Nb位的扩散反应，在Nb_3Al超导体中分散有许多小孔。研究结果表明，经过RHQ热处理的Nb_3Al前驱丝结构简单，具有很好的高场应用前景。
In this paper, we have reported the manufacture of a novel simple-structured jelly-roll Nb3Al precursor long wire, and its electromagnetic properties and microstructure with different rapid heating and quenching (RHQ) heat-treatments. By comparing three processing methods, it is found that the rolling and drawing (RD) method is more suitable to the fabrication of kilometer-length Nb3Al precursor wire without annealing. Using homemade RHQ equipment, we have successfully carried out RHQ heat-treatment of Nb3Al wire samples with various heating conditions. Based on magnetization and magnetoresistivity measurements, the onset superconducting transition temperature, Tc and upper critical field, Hc2 (0) of optimal Nb3Al wire reach 17.9 K–18.0 K and 29.7 T, respectively. Through microstructure and composition analysis, the Nb3Al superconductor in the optimal wire displays a typical ‘layer-to-layer’ structure, which comprises alternate crystalline Nb3Al and amorphous Nb layers, and the Nb3Al grains sizes are about 100 nm–300 nm. Furthermore, many small holes are dispersed in the Nb3Al superconductor due to the diffusion reaction from Al to Nb site. The work suggests the simple-structured Nb3Al precursor wire with RHQ heat-treatment is very promising for high-field application.