Фазовая диаграмма системы Sn-V

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Sn-V (Tin-Vanadium) J.F. Smith The assessed phase diagram for the V-Sn system is a composite of all available data, but is based primarily on the work of [73Mar]. An intermediate phase near "V3Sn" was first reported by [55Gel]. The composition of this phase is 20 at.% Sn. [73Mar] reported a narrow range of homogeneity of 20 to 21 at.% Sn. " V3Sn" exhibits a superconducting transition near -269.2 C (3.8 K), and [64Hau] reported evidence, in some specimens at least, of a martensitic transition near -268 C (5 K). Liquidus data are lacking for intermediate compositions of 47 to 99 at.% Sn. The contour of the assessed liquidus was drawn arbitrarily through this intermediate region by a smooth upward extrapolation of the data of [69Dar] to develop a monotectic reaction consistent with the reproducible thermal arrests found near 1500 C by [73Mar] in 21 to 80 at.% Sn alloys. On the Sn-rich side of "V3Sn", [73Mar] observed two thermal arrests in addition to the peritectic arrest near 1600 C and the monotectic arrest near 1500 C. The first additional thermal arrest was found near 750 C and was interpreted as due to peritectic formation of V2Sn3 from reaction of the liquid with "V3Sn". The second additional thermal arrest shows data points scattered over the range 200 to 260 C. This lowest arrest is most probably associated with the melting of Sn, with the occurrence over the complete composition range being due to incomplete reaction between liquid Sn and "V3Sn" . 55Gel: S. Geller, B.T. Matthias, and R. Goldstein, J. Am. Chem. Soc., 77, 1502- 1504 (1955). 64Hau: J. J. Hauser, Phys. Rev. Lett., 13, 470-471 (1964). 67Jou: F. Jouault and P. Lecocq, Coloq. Int. Centre Nat. Recherche Sci., (157), 229-235 (1967). 69Dar: J.B. Darby and D.B. Jugle, Trans. Met. Soc. AIME, 245, 2515-2518 (1969). 73Mar: L.V. Marchukova, N.M. Matveyeva, and I.I. Kornilov, Russ. Metall., (2), 157-159 (1973). Published in Phase Diagrams of Binary Vanadium Alloys, 1989, and Bull. Alloy Phase Diagrams, 2(2), Sep 1981. Complete evaluation contains 2 figures, 1 table, and 22 references. 1