Фазовая диаграмма системы Au-Dy

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Au-Dy

Au-Dy (Gold-Dysprosium) K.A. Gschneidner, Jr., F.W. Calderwood, H. Okamoto, and T.B. Massalski The Dy-Au system is characterized by the existence of six intermetallic compounds and four eutectics. The rare earth-rich compound is Dy2Au, which decomposes peritectically at 1065 C. Three intermediate compounds-DyAu, DyAu2, and DyAu3-melt congruently at 1660, 1320, and 1230 C, respectively. The assessed phase diagram is based on the work of [73Mcm]. Dy2Au crystallizes in the orthorhombic Co2Si-type structure. DyAu crystallizes in two forms-the low-temperature form is the orthorhombic CrB-type structure and the high-temperature form is the cubic CsCl-type structure. DyAu2 has the tetragonal structure of the MoSi2 type. DyAu3 has an orthorhombic structure of the Cu3Ti type, whereas Dy14Au51 crystallizes in the hexagonal Gd14Ag51-type structure. The solid solubility of Au in (Dy) was reported by [73Mcm] to be negligible, because the lattice parameters of Dy-rich specimens that had been heated at and quenched from 650 and 900 C were the same as those for unalloyed Dy, within experimental error. [65Rid] reported that the maximum solubility of Dy in (Au) is 2.3 at.% at 808 C, decreasing to about 0.5 at.% Dy at 300 C. 65Rid: P.E. Rider, K.A. Gschneidner, Jr., and O.D. McMasters, Trans. AIME, 233, 1488 (1965). 73Mcm: O.D. McMasters and K.A. Gschneidner, Jr., J. Less-Common Met., 30, 325 ( 1973). Published in Phase Diagrams of Binary Gold Alloys, 1987. Complete evaluation contains 3 figures, 2 tables, and 19 references. 1