عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Nb3Sn superconductor compound is the most widely used material for generating magnetic fields above 10T. But, this intermetallic compound is obtained by thermal reactions at high temperatures (>2000°C). Therefore, in recent years the researchers have investigated the processes that permit the formation of the Nb3Sn superconducting phases at lower temperatures (<1000°C). The aim of this study was preparation of nanocrystalline Nb3Sn intermetallic compound using mechanical alloying and heat treatment at low temperature. The phase transitions of milled powder before and after the heat treatment were characterized using X-ray diffractometry (XRD). The microstructural analyses were performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The grain size and lattice strain were calculated using the Williamson-hall method. During the milling, mechanical alloying of Nb-Sn elemental powders resulted in the formation of a solid solution, while the heat-treatment led to the formation of Nb3Sn phase. The results showed that Nb3Sn XRD peaks appeared after the heat treatment at 600°C for the powder milled for 10h.
 K. Krauth, Handbook of applied superconductivity, edited by B. Seeber. IOP. Lodon. 1 (1998) 397-488.
 R. Aymar, ITER R&D: executive summary: design overview, Fusion Engineering and Design, 55 (2001) 107-118.
 N. Ayai, A. Mikumo, Y. Yamada, K. Takahashi, K. Sato, Improvement of critical current density and residual resistivity on jelly-roll processed Nb3Al superconducting wires, Applied Superconductivity. 7 (1997) 1564-1567.
 Y. Yamada, N. Ayai, A. Mikumo, M. Ito, K. Hayashi, Development of Nb3Al superconductors for international thermonuclear experimental reactor (ITER), Cryogenics. 39 (1999) 115-122.
 F.A. Santos, A.S. Ramos, C. Santos, D. Rodrigues Jr, Obtaining and stability verification of superconducting phases of the Nb-Al and Nb-Sn systems by mechanical alloying and low-temperature heat treatments, Journal of Alloys and Compounds. 491 (2010) 187-191.
 S.N. Patankar, F.H. Froes, Formation of Nb3Sn using mechanically alloyed Nb-Sn powder, Solid State Science. 6 (2004) 887-890.
 S.N. Patankar, F.H. Froes, Transformation of mechanically alloyed Nb-Sn powder to Nb3Sn, Metallurgical and Materials Transactions A, 35 (2004) 3009-3012.
 M. Lopez, J.A. Jimenez, K. Raman, R.V. Mangalaraja, Synthesis of nano intermetallic Nb3Sn by mechanical alloying and annealing at low temperature, Journal of Alloys and Compounds, 612 (2014) 215-220.
 A.R. Kaufmann, J.J. Pickett, Multifilament Nb3Sn superconducting wire, Journal of Applied Physics, 42 (1971) 58-67.
 L.D. Cooley, Y.F. Hu, A.R. Moodenbaugh, Enhancement of the upper critical field of Nb3Sn utilizing disorder introduced by ball milling the elements, Applied Physics Letters, 88 (2006) 142506-3.
 B.A. Glowaki, D.J. Fray, X-Y. Yan, G. Chen, Superconducting Nb3Sn intermetallics made by electrochemical reduction of Nb2O5-SnO2 oxides, Physica C, 387 (2003) 242-246.
 X-Y. Yan, D.J. Fray, Electrosynthesis of NbTi and Nb3Sn superconductors from oxide precursors in CaCl2-based melts, Advanced Functional Materials, 15 (2005) 1757-1761.
 C. Suryanarayana, Mechanical alloying and milling, Progress in Materials Science, 46 (2001) 1-180.
 R. Sen, G.Ch. Das, S.M. Jee, X-ray diffraction line profile analysis of nano-sized cobalt in silica matrix synthesized by sol–gel method, Journal of Alloys and Compounds, 490 (2010) 515-523.
 G.K. Williamson, W.H. Hall, X-ray line broadening from filed aluminium and wolfram, Acta Metallurgica, 1 (1953) 22–31.
 P. Villars, L.D. Calvert, Pearson’s handbook of crystallographic data for intermetallic phases, American Society for Metals, Metals Park, (1985).
 M.K. West, PhD Thesis, Processing and characterization of oxide dispersion strengthened 14 YWT ferritic alloys, University of Tennesse, Knoxville, (2006).
 B. Pandey, M.A. Rao, H.C. Verma, S. Bhargava, Structural and compositional changes during mechanical milling of the Fe-Cr system, Journal of Physics Condensed Matter, 6 (2005) 7981-7993.
 J.L. Jorda, H.U. Flukiger, J. Muller, A new metallurgical investigation of the niobium-aluminium system, Journal of the Less Common Metals, 75 (1980) 227-239.
 P.E. Johnson, Y. IM, L.T. Mcknelly, J.W.Jr. Morris, Formation of Nb3Al in Nb-Al superconductors by powder process, Magnetics, IEEE Transactions, 23 (1987) 1432-1435.
 K. Barmak, K.R. Coffey, D.A. Rudman, S. Foner, Phase formation sequence for the reaction of multilayer thin films of Nb/Al, Journal of Applied Physics, 67 (1990) 7313-7322.
 C.C. Koch, Intermetallic matrix composites prepared by mechanical alloying-a review, Materials Science and Engineering, 244 (1998) 39-48.
 M.S. Kim, C.C. Koch, Structural development during mechanical alloying of crystalline niobium and tin powders, Journal of Applied Physics, 62 (1987) 3450-3453.
 J.W. Edindton, Electron diffraction in the electron microscope, London, Macmillan (1975).