Фазовая диаграмма системы Cu-La

К оглавлению: Другие диаграммы (Others phase diargams)

Cu-La (Copper-Lanthanum) D.J. Chakrabarti and D.E. Laughlin The equilibrium phases of the Cu-La system are (1) the liquid, L; (2) the fcc terminal solid solution, (Cu), with insignificant solubility of La; (3) the stoichiometric compound Cu6La, stable up to the congruent melting temperature of 905 C; (4) the stoichiometric compound Cu5La, stable up to the peritectic decomposition temperature of 805 C; (5) the stoichiometric compound Cu2La, stable up to the congruent melting temperature of 830 C; (6) the stoichiometric compound CuLa, stable up to the peritectic decomposition temperature of 525 C; (7) the hexagonal (aLa) solid solution, with insignificant terminal solubility of Cu and stable up to the bLa = aLa transition temperature at about 310 C; (8) the fcc (bLa) solid solution, with insignificant terminal solubility of Cu and stable between about 310 C and the gLa = bLa transition temperature at about 865 C; and (9) the bcc (gLa) solid solution, with insignificant terminal solubility of Cu and stable between about 865 C and the melting temperature of La at 918 C. The assessed phase diagram for the Cu-La system is derived from [77Cir], based on differential thermal analysis, X-ray diffraction (single crystal and powder) , and microscopic studies of alloys made from 99.999% Cu and 99.9% nominal purity La. The accuracy of the recorded temperature is с5 C. The effect of rapid solidification on splat-cooled alloys of 33 to 100 at.% La was studied by [80Fav]. The results are inconclusive. The suspected amorphous phase near the eutectic composition, based on the X-ray indication of a broad intensity maximum, was later identified by electron microscopy to be microcrystalline and made up of crystals about 2.0 nm in diameter. 77Cir: S. Cirafici and A. Palenzona, J. Less-Common Met., 53(2), 199-203 (1977) . 80Fav: J. Favaron, M.E. de la Cruz, P. Esquinazi and F. de la Cruz, Phys. Rev. B., 21(7), 2804-2808 (1980). Published in Bull. Alloy Phase Diagrams, 2(3), Dec 1981. Complete evaluation contains 1 figure, 3 tables, and 17 references. Special Points of the Cu-La System