Adoption of powder-in-tube method to fabricatesuperconducting wire can realize a large application ofNb3Al prepared by powder metallurgy. Powder metallurgywas used to synthesize Nb3Al under various heat-treatmentcondi...Adoption of powder-in-tube method to fabricatesuperconducting wire can realize a large application ofNb3Al prepared by powder metallurgy. Powder metallurgywas used to synthesize Nb3Al under various heat-treatmentconditions, annealing temperature was varied from 700 to1,000 C and heating time was varied from 10 to 50 h.X-ray diffraction patterns reveal that a reaction between Nband Al took place and formed NbAl3 phase. Under currentheat-treatment conditions （annealing temperature wasvaried from 700 to 1,000 C and heating time was variedfrom 10 to 50 h）, NbAl3 was so stable that it did not furtherreact with the unreacted Nb and was not sensitive to theheat-treatment condition. By mechanical alloying, adoptionof high-energy ball milling significantly decreases particlesize and enhances surface free energy, which promotes theformation of Nb3Al phase. X-ray diffraction patternsindicate that relatively pure Nb3Al phase was obtainedunder the same heat-treatment condition. Energy-dispersiveX-ray analysis measurement demonstrates that theobtained samples were close to the right stoichiometry ofA15 structure Nb3Al.展开更多
基金supported by the National Magnetic Confinement Fusion Science Program (Grant No. 2011 GB112001)the Program of International S&T Cooperation (Grant No. 2013DFA51050)+3 种基金the National Natural Science Foundation of China (Grant Nos. 11104224, 11004162, 51377138, and 51302224)the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20110184120029)the Fundamental Research Funds for the Central Universities (Grant Nos. 2682013ZT16, SWJTU11ZT31, 2682013CX004, and SWJTU11BR063)the Science Foundation of Sichuan Province (Grant Nos. 2011JY0031 and 2011JY0130)
文摘Adoption of powder-in-tube method to fabricatesuperconducting wire can realize a large application ofNb3Al prepared by powder metallurgy. Powder metallurgywas used to synthesize Nb3Al under various heat-treatmentconditions, annealing temperature was varied from 700 to1,000 C and heating time was varied from 10 to 50 h.X-ray diffraction patterns reveal that a reaction between Nband Al took place and formed NbAl3 phase. Under currentheat-treatment conditions （annealing temperature wasvaried from 700 to 1,000 C and heating time was variedfrom 10 to 50 h）, NbAl3 was so stable that it did not furtherreact with the unreacted Nb and was not sensitive to theheat-treatment condition. By mechanical alloying, adoptionof high-energy ball milling significantly decreases particlesize and enhances surface free energy, which promotes theformation of Nb3Al phase. X-ray diffraction patternsindicate that relatively pure Nb3Al phase was obtainedunder the same heat-treatment condition. Energy-dispersiveX-ray analysis measurement demonstrates that theobtained samples were close to the right stoichiometry ofA15 structure Nb3Al.
文摘使用自主研发的快热快冷处理设备,对粉末装管Nb/Al前驱线进行快热快冷处理,然后再经过800℃10 h转变退火处理,得到具有Nb3Al超导相的超导短样.通过扫描电镜观察分析超导样品微观结构,发现所有样品均有Nb3Al相存在,但在靠近Ta管内层有少量的Nb2Al相,超导芯内有少量的Nb剩余.在制冷机冷却的环境下使用四引线法测试了样品的超导性能.结果表明,自场下在10.9 K温度时,没有铜稳定体的Nb3Al超导线最高临界电流密度是66.5 A/mm2,超导起始转变温度是15~18 K.
