Фазовая диаграмма системы Ag-Cr

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Ag-Cr (Silver-Chromium) M. Venkatraman and J.P. Neumann The assessed equilibrium Cr-Ag phase diagram is based on the studies of [08Hin] , [54Gri], and [67All]. It is characterized by essential immiscibility of Cr and Ag in the liquid and solid states and by the absence of intermediate phases. The assessed diagram is similar to that of [Hansen], which was based on [54Gri]. The boundaries of the liquid miscibility gap above the monotectic temperature have not been established. In drawing the assessed diagram, it was assumed that the liquid exhibits ideal behavior. The enthalpy of melting and the melting temperature of pure Ag are taken as 11.3 kJ/mol [Hultgren,E] and 961. 93 C [Melt], respectively. The absence of intermediate phases was confirmed by the thin-film studies of [78Sim]. The solubility of solid Cr in liquid Ag was measured by [67All]. Extrapolation of experimental data to the monotectic temperature, 1450 C, yields a value of 3 at.% Cr for the solubility. [81Neu] determined the solubility of solid Cr in solid Ag in the temperature range 700 to 960 C. Extrapolation to the eutectic temperature of ~961 C yields a value of 0.01 at.% Cr for the solubility of Cr in (Ag). Formation of a metastable solid solution of Cr in Ag beyond the equilibrium concentration was observed by [83Nin], who quenched liquid Ag-rich alloys at cooling rates of 105 to 106 K/s. The observed metastable solid solubility limit corresponds to the solubility of Cr in liquid Ag at the monotectic temperature. 08Hin: G. Hindrichs, Z. Anorg. Chem., 59, 414-449 (1908) in German. 54Gri: A.T. Grigorev, E.M. Sokolovskaya, and M.I. Kruglova, Vestn. Mosk. Univ. Ser. Fiz.-Mat. Estest. Nauk, 9(5), 77-81 (1954) in Russian. 67All: B.C. Allen, Trans. Metall. Soc. AIME, 239, 1026-1029 (1967). 78Sim: V. Simic and Z. Marinkivic, Naucno Teh. Pregl., 28, (2) 3-12 (1978) in Serbo-Croatian. 81Neu: G. Neumann, M. PfЃndstein, and P. Reimers, Phys. Status Solidi A, 64, 225-232 (1981). 83Nin: Y. Ning, Chin Shu Hsueh Pao, 19(4) A316-A353 (1983) in Chinese. Published in Bull. Alloy Phase Diagrams 11(3), Jun 1990. Complete evaluation contains 2 figures, 1 table, and 8 references. 1