Фазовая диаграмма системы Au-Tm

К оглавлению: Другие диаграммы (Others phase diargams)


Au-Tm (Gold-Thulium) K.A. Gschneidner, Jr., F.W. Calderwood, H. Okamoto, and T.B. Massalski Although the stoichiometry and structural data have been reported for five intermetallic compounds in the Tm-Au system, the entire phase diagram has not been established experimentally. Therefore, the assessed phase diagram has been calculated. With the exception of TmAu, no melting point data are available for the compounds in this system. [71Mcm] reported that Tm2Au crystallizes with the orthorhombic Co2Si-type structure. They also found that TmAu is dimorphic, the a form crystallizing in the orthorhombic CrB-type structure and the b form in the cubic CsCl-type structure. [63Cha] also reported the cubic structure,which they obtained in splat-cooled and slow-cooled TmAu compositions. The melting temperature of TmAu was reported to be 1720 с 10 C by [71Mcm]. They did not detect the b = a transformation temperature for this compound. TmAu2 crystallizes in the tetragonal MoSi2-type structure. TmAu3 crystallizes in the orthorhombic Cu3Ti-type structure. The Au-rich compound, TmAu4, crystallizes in the tetragonal MoNi4-type structure. The solid solubility of Tm in Au-rich alloys has been investigated by [65Rid], who reported that a maximum of 6.5 at.% Tm is soluble in (Au) at 842 C, the temperature for the eutectic between (Au) and TmAu4. 63Cha: C.C. Chao, H.L. Luo, and P. Duwez, Jr., J.Appl. Phys., 34, 1971 (1963). 65Rid: P.E. Rider, K.A. Gschneidner, Jr., and O.D. McMasters, Trans. AIME, 233, 1488 (1965). 71Mcm: O.D. McMasters, K.A. Gschneidner, Jr., G. Bruzzone, and A. Palenzona, J. Less-Common Met., 25, 135 (1971). Published in Phase Diagrams of Binary Gold Alloys, 1987. Complete evaluation contains 3 figures, 2 tables, and 13 references. 1