Фазовая диаграмма системы V-Zr

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V-Zr (Vanadium-Zirconium) J.F. Smith The assessed phase diagram for the V-Zr system is based primarily on the investigation of [69Rud] of the phase relationships. However, there is general agreement as to the major features of the diagram [54Ros, 55Wil, 74Sve]. [55Wil] indicated negligible solubility of V in (aZr) and a negligible range of homogeneity for the intermediate V2Zr phase. [69Rud] showed the probability of a small, but finite, solubility of V in (aZr) and showed the V2Zr phase field to have a width on the order of an atom percent on the Zr-rich side of ideal stoichiometry. Both diagrams show good agreement with respect to the solubility of V in (bZr). On the V-rich side of the diagram, [Elliott] quotes Russian work as indicating the following solubilities of Zr in V: 0.56 at.% at 1800 C, 1.9 at.% at 1600 C, 4.2 at.% at 1400 C, 5.2 at.% at the 1300 C eutectic temperature, 3.7 at.% V at 1100 C, 2.6 at.% at 700 C, and 1.9 at.% at room temperature. Below room temperature, V2Zr has been widely studied because a martensitic transition has been reported in the range 100 to 130 K [82Koz], and a superconducting transition temperatures in the range 7 to 9 [83Bul]. The superconducting transition temperature varies somewhat with composition and reaches a maximum at ideal stoichiometry [78Fin]. This supports the assignment of a finite width to the phase field. Neutron irradiation reduces Tc in V2Zr and HfV2 phases with the C15-type structure by only 5 to 10%, whereas in comparison, superconductors with the A15-type structure fall by 60 to 90% [ 84Nas]. There is some evidence that the martensitic transformation is actually two transformations<311>a second-order electronic transition followed by a first- order crystallographic transition at a temperature a few degrees lower [82Bal] . Measurements of electronic properties such as resistivity [80Fin] or magnetic susceptibility [81Gal] show evidence of a transition near 120 K. Quenching from the (bZr) phase field can produce a hexagonal w phase with a = 0.502 nm and c = 0.300 nm [60Hat]. Quenching of foils on the Zr-rich side of V2Zr has been shown to produce a variety of phase mixtures, including one or more with bcc, cph, V2Zr, or amorphous structures [80Ten]. Near 60 at.% Zr, rapid quenching resulted in amorphous material with no other phases detected. 54Ros: W. Rostoker and A. Yamamoto, Trans. ASM, 46, 1136-1167 (1954). 55Wil: J.T. Williams, Trans. Metall. Soc. AIME, 203, 345-350. (1955). 60Hat: B.A. Hatt and J.A. Roberts, Acta Metall., 8, 575-584 (1960). 69Rud: E. Rudy, Compendium of Phase Diagram Data, U.S. Report AFML-TR-65-2, Part V, Air Force Materials Laboratory, Wright Patterson AFB, 8 and 75-76 ( 1969). 74Sve: V.N. Svechnikov, Yu.A. Kocherzhinskii, G.F. Kobzenko, V.M. Pan, and A.K. Shurin, Metallofizika, 52, 3-22 (1974) in Russian. 78Fin: T.R. Finlayson and H.R. Khan, Appl. Phys., 17, 165-172 (1978). 80Fin: V.A. Finkl and E.A. Pushkarev, Zh. Eksp. Teor. Fiz., 78, 842-846 (1980); Sov. Phys.<311>JETP, 51, 422-424 (1980). 80Ten: M. Tenhover, Appl. Phys., 21, 279-282 (1980). 81Gal: E.V. Galoshina, V.N. Kozhanov, S.V. Verkhovskii, M.A. Borozdina, Ye.P. Romanov, T.S. Shubina, and K.N. Mikhalev, Fiz. Met. Metallloved., 52, 1205- 1214 (1981) in Russian; TR: Phys. Met. Metallogr., 52, (6), 68-76 (1981). 82Bal: A.S. Balankin, Fiz Tverd. Tela (Leningrad), 24, 3474-3477 (1982) in Russian; TR: Sov. Phys. Solid State, 24, 1977-1978 (1982). 82Koz: V.N. Kozhanov, V.B. Pushkin, Ye.P. Romanov, R.R. Romanova, and N.N. Syutkina, Fiz. Met. Metalloved., 53, 1090-1096 (1982) in Russian; TR: Phys. Met. Metallogr., 53, (6) 41-46 (1982). 83Bul: I.E. Bulakh, A.M. Gabovich, A.E. Morozovskii, V.M. Pan, and S.S. Shpigel, Fiz. Tverd. Tela (Leningrad), 25, 880-882 (1983) in Russian; TR: Sov. Phys. Solid State, 25, 504-505 (1983). 84Nas: A.I. Nashkidashvili, I.A. Nashkidashvili, L.S. Topchyan, V.N. Kozhanov, and E.P. Romanov, Fiz. Met., Metalloved., 57, 205-208 (1984) in Russian; TR: Phys. Met. Metallogr., 57(1), 194-197 (1984). Published in Phase Diagrams of Binary Vanadium Alloys, 1989. Complete evaluation contains 1 figure, 3 tables, and 39 references. Special Points of the V-Zr System