Фазовая диаграмма системы V-Y

К оглавлению: Другие диаграммы (Others phase diargams)

V-Y (Vanadium-Yttrium) J.F. Smith and K.J. Lee The calculated phase diagram for the V-Y system accords with the major features of the diagrams proposed by [60Lov], [61Lun], and [62Lun] and was obtained by thermodynamic modeling. The diagrams of [60Lov], [61Lun], and [ 62Lun] showed extensive immiscibility in liquid and solid states, a monotectic reaction near the melting point of V, and a eutectic reaction between cph Y and bcc V. None of these investigators defined the effect of V on the cph = bcc transition of Y, but the calculated diagram indicates that V causes a slight peritectic elevation in the transition temperature. Composite data [ 59Sav, 60Lov, 64Obr, 71Sve] indicate that the solubility of Y in (V) is quite small. [61Lun] and [62Lun] reported the solubility of V in (Y) to be less than 0.17 at.% at all temperatures up to 1400 C (1673 K), with a slight increase above 1400 C to 0.3 с 0.17 at.% V (XY ~ 0.997) at the eutectic reaction at 1455 C ( 1728 K). At the eutectic equilibrium, the composition for the liquid was given as 11.6 at.% V (XY = 0.884), and the solubility of Y in (V) was shown as negligible (XY ~ 0). [61Lun] and [62Lun] speculated that the solubility of V in bcc (Y) should be greater than in cph (Y), which would then result in a depression in the temperature of the cph = bcc transition. This is inverse to the calculated change, and it should be emphasized that there is no experimental support either for this speculation or for the calculated result. 59Sav: E.M. Savitskii and V.F. Terekhova, Tsvetn. Metall, (1), 48-53 (1959) in Russian; TR: Jan Woroncow, General Electric, Atomic Products Division, Aircraft Nuclear Propulsion Program (6 Aug 1959). 60Lov: B. Love, Wright Air Development Division Tech. Rep. No. 60-74, 61, 123, and 215 (1960). 61Lun: C.E. Lundin, Jr. and D.T. Klodt, Trans. ASM, 53, 735-742 (1961). 62Lun: C.E. Lundin, Jr. and D.T. Klodt, J. Inst. Met., 90, 341-347 (1962). 64Obr: W.L. O'Brien and E.A. Rowe, U.S. Bur. Mines Rep. of Invest. No. 6553 ( 1964). 71Sve: V.N. Svechnikov, V.M. Pan, and A.Ts. Spektor, Dokl. Akad. Nauk SSSR, 198, 377-379 (1971) in Russian; TR: Dokl. Phys. Chem., 198, 416-418 (1971). Published in Phase Diagrams of Binary Vanadium Alloys, 1989. Complete evaluation contains 1 figure, 2 tables, and 15 references. Special Points of the V-Y System