Фазовая диаграмма системы Cu-Y

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Cu-Y

Cu-Y (Copper-Yttrium) D.J. Chakrabarti and D.E. Laughlin The equilibrium phases of the Cu-Y system are (1) the liquid, L; (2) the fcc terminal solid solution, (Cu), with negligible (<0.04 at.%) solubility of Y; ( 3) the cph terminal solid solution, (aY), with marginal solubility of Cu, ( maximum between 0.07 and 0.14 at.%) and stable up to 1478 C; (4) the bcc terminal solid solution, (bY), stable between the bY = aY transition temperature at 1478 C and the melting point of bY at 1522 C, presumably having negligible solubility of Cu; (5) the compound Cu6Y, stable up to the peritectic decomposition temperature of 910 с 5 C; (6) the compound Cu4Y, stable over a compositional field whose boundaries have not been determined and up to the congruent melting temperature at 975 с 5 C; (7) the stoichiometric compound Cu7Y2, stable up to the peritectic decomposition temperature at 920 с 5 C; (8) the stoichiometric compound Cu2Y, stable up to the congruent melting temperature at 935 с 15 C; and (9) the stoichiometric compound CuY, stable up to the congruent melting temperature at 935 с 15 C. The assessed phase diagram is based primarily on the work of [61Dom], with modifications from [66Bea]. The available information on the Cu-Y system is incomplete with regard to the liquidus, and the various transition temperatures also have not been determined accurately. However, the diagram is otherwise fairly complete with regard to the establishment of the coexisting equilibrium phases. Although equilibrium solubility of Cu in (Y) is very restricted, metastable extension of the solid solubility limit up to 20 at.% Cu has been obtained by ultrarapid quenching of the melt at the rate of ~108 C/s. Under the rapid solidification conditions of splat cooling, [71Bus] succeeded in synthesizing a single-phase Cu5Y compound at the stoichiometric composition, thus confirming its occurrence as a metastable phase. 61Dom: R.F. Domagala, J.J. Rausch, and G.W. Levinson, Trans. ASM, 53, 137-155 and 899-903 (1961). 66Bea: B.J. Beaudry, private communication of unpublished results of 1966, Ames Laboratory, Iowa State University, Ames (1966). 71Bus: K.H.J. Buschow and A.S. van der Goot, Acta Crystallogr. B, 27(6), 1085- 1088 (1971). Published in Bull. Alloy Phase Diagrams, 2(3), Dec 1981. Complete evaluation contains 1 figure, 4 tables, and 21 references. Special Points of the Cu-Y System