Фазовая диаграмма системы La-Ti

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La-Ti (Lanthanum-Titanium) J.L. Murray The equilibrium solid phases of the Ti-La system are those based on the pure elements-bcc (bTi) and cph (aTi), the high- and low-temperature forms, respectively; and bcc (gLa) and fcc (bLa), high- and low-temperature forms of La in the temperature range under consideration above 600 C; dcph (aLa) is stable below 310 C. The Ti-La system contains no intermetallic phases and has a miscibility gap in the liquid phase. The only published experimental study of the system [57Sav, 62Sav] is limited both in the range examined and in the purity of the alloys. [57Sav] and [62Sav] studied the diagram in the range of 0 to 7 at.% La by microscopy, thermal analysis, and dilatometry, and the measurements were probably accurate to about 10 C, respectively. The other invariant temperatures appear to have been determined by microscopic methods, and they have an unknown but larger uncertainty. The solubility of La in (aTi) or (bTi) was found to be about 1 at.% over the entire range examined (600 to 1600 C). Those Ti-rare earth phase diagrams for which more accurate and extensive data are available can be calculated from Gibbs energies that nearly approximate regular or subregular solutions. A thermodynamic calculation has been used to test the self-consistency of the diagram reported by [57Sav] and [62Sav]. The assessed diagram is the result of the calculation. 57Sav: E.M. Savitskii and G.S. Burkhanov, Zh. Neorg. Khim., 2(11), 2609-2616 ( 1957) in Russian; TR: J. Inorg. Chem., 2, 199-219 (1957). 62Sav: E.M. Savitskii and G.S. Burkhanov, J. Less-Common Met., 4, 301-314 ( 1962). Published in Phase Diagrams of Binary Titanium Alloys, 1987. Complete evaluation contains 1 figure, 3 tables, and 3 references. Special Points of the Ti-La System