Фазовая диаграмма системы Dy-Mg

К оглавлению: Другие диаграммы (Others phase diargams)


Dy-Mg (Dysprosium-Magnesium) A.A. Nayeb-Hashemi and J.B. Clark The assessed phase diagram for the Mg-Dy system is based on review of the experimental data [64Mil, 65Jos, 78Rok]. It is generally agreed that four intermetallic compounds (Mg24Dy5, Mg3Dy, Mg2Dy, and MgDy) occur in the system. However, their phase boundaries remain to be determined. [64Mil] reported that MgDy forms by a peritectic reaction at 857 с 5 C. They also indicated that an 80 at.% Dy alloy had a liquidus temperature slightly below 1240 C. The mechanisms of formation of the other compounds have not been determined. However, from homologous Mg-RE systems, it appears that these compounds also form by peritectic reactions. The maximum solid solubility of Dy in (Mg) was shown as 4.83 at.% Dy at the eutectic temperature, 561 C [78Rok]. The maximum solid solubility of Mg in (aDy) at the eutectoid decomposition temperature (706 C) of (bDy) was placed at 13.5 at.% Mg by extrapolation [64Mil]. 64Mil: A.E. Miller and A.H. Daane, Trans. Metall. Soc. AIME, 230, 568-572 ( 1964). 65Jos: R.R. Joseph and K.A. Gschneidner, Jr., Trans. Metall. Soc. AIME, 233, 2063-2069 (1965). 78Rok: L.L. Rokhlin, Probl. Metalloved Tsvetn. Splavov, N.M. Zhavoronkov, Ed., Izd. Nauka, Moscow, 59-70 (1978) in Russian. Published in Phase Diagrams of Binary Magnesium Alloys, 1988. Complete evaluation contains 1 figure, 7 tables, and 25 references. Special Points of the Mg-Dy System