Фазовая диаграмма системы D-V

К оглавлению: Другие диаграммы (Others phase diargams)


Cd-V (Cadmium-Vanadium) J.F. Smith Because very limited experimental data are available concerning the phase relationships in the Cd-V system, the assessed phase diagram was calculated from the available thermomechanical data. This diagram represents the phase relationships for a constrained system wherein pressure is maintained sufficiently high to keep all phases in condensed form. The value for the solubility of V in both solid and liquid Cd near the Cd melting point was calculated to be X < 10-8. Such small solubilities may be expected to produce a negligible effect on the melting of Cd. Therefore, no attempt was made to compute a level of peritectic elevation or eutectic depression of that melting point. The most reliable information concerns the solubility of V in Cd [62Cha]. It was determined that the solubility of V in liquid Cd at 650 C (973 K) was 0.2 wt. ppm (0.4 at. ppm). Two other reports [63Hol, 66Sav] concerning the phase relationships in the system indicate the existence of an intermediate phase with the Cr3Si structure at a stoichiometry of CdV3; these reports are both viewed quite skeptically, due to possible contamination effects from the testing procedures. Overall, the existence of CdV3 as an equilibrium phase in the pure binary Cd-V system at ambient pressure is sufficiently questionable that the phase was not considered in the calculation of the assessed phase diagram. The data of [80Deb] agree with the present calculated diagram to the extent that they indicate mutual immiscibility between liquid alloy and solid V and very limited terminal solubilities of V in (Cd) or of Cd in (V). 62Cha: M.G. Chasanov, P.D. Hunt, I. Johnson, and H.M. Feder, Trans. AIME, 224, 935-939 (1962). 63Hol: H. Holleck, H. Nowotny, and F. Benesovsky, Monatsh. Chem., 94, 473-476 ( 1963). 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). 80Deb: F.R. DeBoer, R. Boom, and A.R. Miedema, Physica B, 101, 294-319 (1980). Published in Phase Diagrams of Binary Vanadium Alloys, 1989. Complete evaluation contains 1 figure, 1 table, and 18 references. Special Points of the Cd-V System