Trial Manufacturing of Jelly-Rolled Nb/Al Monofilamentary Wire with Very Small Diameter below 50 microns
Trial Manufacturing of Jelly-Rolled Nb/Al Monofilamentary Wire with Very Small Diameter below 50 microns
复制标题
50微米以下极小直径胶状轧制铌铝单丝试制
DOI：
10.1088/1757-899x/756/1/012016
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Tsuchiya Kiyosumi
中科院分区：
文献类型：
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作者：
Kikuchi Akihiro;Iijima Yasuo;Ichinose Ataru;Kawano Masatoshi;Yamamoto Masaru;Kimura Motoyoshi;Nagamatsu Jun;Otsubo Masato;Hirata Kazuto;Nimori Shigeki;Tsuchiya Kiyosumi
成功地制备了外径50 μ m、长度超过100 m的凝固轧制Nb/Al复合单晶线材。此外，在本研究中，这些细线中的一些被额外拉伸至外径为30微米。我们再次认识到，冷轧Nb/Al复合单晶线材具有优良的冷加工性能和拉拔性能。透射电子显微镜观察表明，即使在外径为30 μm的极细的金属丝中，铌和铝叠层在纵向上也保持了类似日本竹子的微结构的纳米级纤维复合结构。铝片的厚度约为70 nm，这几乎与由压下率计算的值相当。在850 ℃下扩散反应10 h后，得到的临界温度分别为16.2 K和15.7 K。外磁场为1 T和8 T时，液氦（4.2K）中的输运临界电流分别为7.2A和0.7A，对应的非Cu临界电流密度分别为15,000和1, 500 A/mm 2。这些值大于工业Nb-Ti和MgB_2商用多芯线材的值。
Jelly-rolled Nb/Al composite monofilamentary wires having an outer diameter of 50 microns and more than 100 meters in length were successfully fabricated. Moreover, some of these thin wires were additional drawn to 30 microns in outer diameter in this study. We recognized again that jelly-rolled Nb/Al composite monofilamentary wires have excellent cold workability and drawability. The transmission electron microscopic observation revealed that the niobium and aluminum laminations retained a nano-scaled fiber composite structure in the longitudinal direction like the microarchitecture of Japanese bamboo, even in the very thin wire with an outer diameter of 30 μm. The thickness of the aluminum sheet is approximately 70 nm, which is almost comparable to the value calculated from the reduction ratio. The critical temperature of 16.2 K (on set) and 15.7 K (off set) were obtained after the diffusion reaction at 850 C for 10 h. The transport critical currents in liquid helium (4.2 K) under external magnetic fields of 1 T and 8 T are 7.2 A and 0.7 A, corresponding to non-Cu critical current densities of 15,000 and 1,500 A/mm 2, respectively. These values are greater than those of industrial Nb-Ti and MgB2 commercial multifilamentary wires.