Фазовая диаграмма системы Er-Y

К оглавлению: Другие диаграммы (Others phase diargams)


Er-Y (Erbium-Yttrium) K.A. Gschneidner, Jr. and F.W. Calderwood The assessed Er-Y phase diagram is based on the data of [73Spe], who used differential thermal analysis, X-ray diffraction, and metallographic methods to investigate the phase equilibria. The thermal analysis data of [64Mar] show good agreement with the work of [73Spe] when the [64Mar] data are adjusted for the differences in the melting points of the "pure metals" that were used by [ 64Mar]. The thermal data points obtained by [73Spe] were shown as single points for the melting temperatures and for the transition temperatures, because the start and the stop of the thermal arrests on both heating and cooling curves were within 1.5 C, the same as for pure metals. The addition of Er to (Y) or of Y to (Er) lowers the melting point to a minimum of 1507 C at 47 at.% Y. Alloys containing less than 53 at.% Er solidify to the bcc structure, which transforms at lower temperatures to the cph structure. Alloys with more than 53 at.% Er crystallize directly to the cph solid solution. The wide separation between the liquidus and solidus lines for these alloys, reported earlier, was due not to the enrichment of one rare earth over the other during freezing, but to the presence of impurities, particularly nonmetallic impurities. The pronounced minima in the melting point or transition temperature of the heavy lanthanide alloy series that have been reported do not occur when the component rare-earth metals are pure, but may result if considerable impurities are present [73Spe]. 64Mar: I.A. Markova, V.F. Terekhova, and E.M. Savitskii, Zh. Neorg. Khim., 9, 2034 (1964); TR: Russ. J. Inorg. Chem., 9, 1098 (1964). 73Spe: F.H. Spedding, B. Sandeen, and B.J. Beaudry, J. Less-Common Met., 31, 1 (1973). Published in Bull. Alloy Phase Diagrams, 4(1), Jun 1983. Complete evaluation contains 2 figures and 3 references. 1