Фазовая диаграмма системы V-Zr
К оглавлению: Другие диаграммы (Others phase diargams)
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