Фазовая диаграмма системы V-Zn

К оглавлению: Другие диаграммы (Others phase diargams)


V-Zn (Vanadium-Zinc) J.F. Smith The assessed phase diagram for the V-Zn system is a composite based on the work of [63Cha], [63Sch], and [65Joh], with review of the data of [65Pio]. Two intermediate phases, V4Zn5 and VZn3, were observed by [63Cha], [63Sch], and [ 65Joh]. [65Pio] indicated the possible existence of a third intermediate phase with bct symmetry at a composition of 94.1 at.% Zn near the stoichiometry of VZn16. Thermal analyses showed this phase as undergoing peritectic melting at a temperature only slightly above the eutectic temperature, but the peritectic reaction was not detectable at cooling rates exceeding 1 C/min. [65Pio] indicated a finite solubility of V in (Zn) with maximum V content occurring at a composition of 99.975 at.% Zn at the eutectic temperature. The liquid composition at the eutectic temperature was found to be 99.55 at.% Zn. This represents a V content almost three times as large as that found by [ 63Cha]. However, thermodynamic considerations indicate that [65Pio] may be correct. [66Sav] reported the possibility of yet a fourth intermediate phase in the V- Zn system at a stoichiometry of V3Zn. [66Sav] found evidence for a V3X phase with the cubic Cr3Si structure, but it was noted that V3Zn needed further confirmation. It seems doubtful that any of these phases are true equilibrium phases in the pure binary systems, but more likely are either metastable or, most likely, impurity-stabilized phases. 63Cha: M.G. Chasanov, R. Schablaske, P.D. Hunt, and B. Tani, Trans. AIME, 227, 485-488 (1963). 63Sch: R. Schablaske, B. Tani, M. Homa, and R. Larsen, USAEC Rep. ANL-6687, 84- 85 (1963). 64Ros: W. Rossteutscher and K. Schubert, Z. Metallkd., 55, 617-618 (1964) in German. 64Sch: K. Schubert, H.G. Meissner, A. Raman, and W. Rossteutscher, Naturwissenschaftern., 51, 287 (1964). 64Wen: Z. Wendorff and W. Piotrowski, Hutnik, 31, 246-249 (1964) in Polish. 65Joh: I. Johnson and I.G. Dillon, USAEC Rep. ANL-7083, 102-105 (1965). 65Pio: W. Piotrowski, Hutnik, 32, 135-142 (1965) in Polish. 66Sav: E.M. Savitskii, V.V. Baron, and Yu.V. Efimov, Dokl. Akad. Nauk SSSR, 171, 331-332 (1966); Sov. Phys. Dokl., 11, 988-989 (1967). Published in Phase Diagrams of Binary Vanadium Alloys, 1989. Complete evaluation contains 1 figure, 3 tables, and 13 references. Special Points of the V-Zn System