Фазовая диаграмма системы Be-Ru

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Be-Ru (Beryllium-Ruthenium) H. Okamoto and L.E. Tanner The assessed phase diagram for the Be-Ru system is based on the experimental work of [63Obr] for the composition range from 18 to 100 at.% Ru. The remainder of the diagram contains three intermediate compounds found more recently; these replace a wide phase field (7 to 16 at.% Ru) identified as Be13Ru in the original diagram of [63Obr] (see [Shunk]). The equilibrium phases in the tentatively assessed Be-Ru diagram are (1) the liquid, L; (2) the terminal solid solutions (bBe) and (aBe); (3) Be12Ru; (4) Bex (x @ 6.6); (5) Be17Ru3; (6) Be10Ru3; (7) Be2Ru; (8) Be3Ru2; and (9) the ( Ru) terminal solid solution. [63Obr] proposed an extended single-phase field between 7 and 16 at.% Ru, with a stoichiometry of Be13Ru. Two additional compounds, Be17Ru2 [ 71Ver] and Be17Ru3 [62San], were found in the presumed phase field of Be13Ru. Furthermore, a stoichiometry of Be12Ru rather than Be13Ru is preferred, based on the atomic radius ratio (r) of the elements (r < 1.33) [79Ald]. This phase enters into a eutectic reaction with (aBe) at about 3 at.% Ru [63Obr], in reasonable agreement with the observation that a slowly cooled alloy of 1 at.% Ru develops a two-phase structure containing ~20% eutectic [50Kau]. [67Ols] observed the superconducting transition temperature of a 5 at.% Ru alloy in the range of 1.50 K, independent of alloy processing, and suggested that superconducting behavior is related to a Be-rich phase, presumably Be12Ru. The solubility of Ru in (aBe) is negligible [55Sta]. The solubility limit of Be in (Ru) is about 1 at.% at ~1420 C [63Obr]. [80Tan] predicted the possible existence of a stable or metastable compound, BeRu, with the CsCl-type crystal structure, from the study of a series of Be- transition metal systems. 50Kau: A.R. Kaufmann, P. Gordon, and D.W. Lillie, Trans. ASM, 42, 785-844 ( 1950). 55Sta: J.T. Stacy, in Reactor Handbook, Vol. 3, Sec. I, General Properties, U. S. Atomic Energy Comm. AECD-3647 (declassified ed.), 92 (1955). 62San: D.E. Sands, Q.C. Johnson, O.H. Krikorian, and K.L. Kromholtz, Acta Crystallogr., 15(12), 1191-1195 (1962). 63Obr: W. Obrowski, Metall, 17(2), 108-112 (1963) in German. 67Ols: C.E. Olsen, B.T. Matthias, and H.H. Hill, Z. Phys., 200, 7-12 (1967). 70Joh: Q. Johnson, G.S. Smith, O.H. Krikorian, and D.E. Sands, Acta Crystallogr. B, 26(2), 109-113 (1970). 71Ver: L.F. Verkhorobin, Izv. Akad. Nauk SSSR, Met., (6), 168-171 (1971); TR: Russ. Metall., (6), 121-122 (1971). 79Ald: F. Aldinger and G. Petzow, in Beryllium Science and Technology, Vol. 1, D. Webster and G.J. London, Ed., Plenum Press, New York, 235-305 (1979). 80Tan: L.E. Tanner, Acta Metall., 28(12), 1805-1816 (1980). 82Mat: N.N. Matyushenko, L.F. Verkhorobin, V.P. Serykh, and N.S. Pugachev, Izv. Akad. Nauk SSSR, Met., (6), 191-193 (1982) in Russian; TR: Russ. Metall., (6), 146-149 (1982). 85Joh: Q.C. Johnson, private communication (1985). Published in Phase Diagrams of Binary Beryllium Alloys, 1988. Complete evaluation contains 1 figure, 1 table, and 14 references. 1