Фазовая диаграмма системы Cu-Yb

К оглавлению: Другие диаграммы (Others phase diargams)

Cu-Yb (Copper-Ytterbium) P.R. Subramanian and D.E. Laughlin [71Ian] determined the phase relations in the Cu-Yb system and reported the existence of five intermediate phases: Cu5Yb, Cu9Yb2, Cu7Yb2, Cu2Yb, and CuYb. The Yb used in their investigation was reported to be 99.9% pure, and the Cu used was 99.999% pure. The phase diagram reported by [71Ian] was based on DTA, metallography, and X-ray diffraction studies. Thermal analysis was carried out using two or more thermal cycles with heating and cooling rates of 10 C/min, 5 C/min, and occasionally 2 C/min to ensure reproducibility. [Moffatt] reproduced the Cu-Yb phase diagram from the data of [71Ian], as well as from an earlier report by the same authors [70Ian], and incorporated minor changes of 1 to 3 C in the various invariant temperatures. The assessed phase diagram for the Cu-Yb system is based on the data of [71Ian] , with minor adjustments in the elemental melting points as well as in the gYb = bYb transformation temperature. The phase diagram of the Cu-Yb system is different from those of Cu with the other heavy lanthanides in that the phases Cu2Yb and CuYb melt peritectically. In contrast, in the other lanthanides, the 2:1 as well as the 1:1 phases melt congruently. These deviations from systematics of alloys of Cu with the heavy lanthanides can be attributed to the divalent nature of Yb in its standard state as compared to the other heavy lanthanides such as Gd, Tb, and Dy, which are usually trivalent in their standard state. On the basis of lattice parameter measurements, [71Ian] determined that there is no appreciable terminal solid solubility in the Cu-Yb system. [79Dri] reported that the maximum solid solubility of Yb in Cu is ~0.03 at.% (~0.07 wt.%) at the eutectic temperature. 70Ian: A. Iandelli and A. Palenzona, Collog. Internat. Les Elements des Terres Rares, Vol. 1, Centre National de la Recherche Scientifique, Paris, 159-175 ( 1970). 71Ian: A. Iandelli and A. Palenzona, J. Less-Common Met., 25, 333-335 (1971). 79Dri: M.E. Drits., N.R. Bochvar, L.S. Guzei, E.V. Lysova, E.M. Padezhnova, L. L. Rokhlin, and N.I. Turkina, Binary and Multicomponent Copper-Based Systems, N.Kh. Aprikosov, Ed., Nauka, Moscow, 25 (1979) in Russian. Published in Bull. Alloy Phase Diagrams, 9(3a), Aug 1988. Complete evaluation contains 2 figures, 6 tables, and 19 references. Special Points of the Cu-Yb System