Фазовая диаграмма системы Ag-Sn

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Ag-Sn (Silver-Tin) I. Karakaya and W.T. Thompson The equilibrium condensed phases of the Ag-Sn system are the liquid (L); the Ag-rich fcc (Ag) solid solution, with a maximum 11.5 at.% Sn solubility; the disordered cph phase, z; the orthorhombic short-range ordered Ag3Sn phase, e; the Sn-rich bct (bSn) phase, with very limited Ag solubility; and (aSn) below 13 C. The diagram is based on review of the experimental data of [1897Hey], [ 07Pet], [26Mur], [34Han], [37Hum], [39Owe], and [40Uma]. The solidus and solvus curves were determined micrographically [26Mur, 34Hum] and by X-ray analysis [39Owe, 40Uma]. The results indicate maximum Sn solubility (at 724 C) of 11.3 at.% [39Owe] and 12.2 at.% Sn [26Mur]. Combining these values with solubilities at lower temperatures [26Mur, 34Hum, 39Owe, 40Uma] indicates an average value of 11.5 at.% Sn at 724 C. The solid solubility of Ag in (bSn) at the eutectic temperature is given as 0. 09 at.% Ag [26Mur, 81Vnu]. Ag-Sn alloy with 4 at.% Ag rapidly quenched to -190 C is reported to be a metastable HgSn-type phase (hexagonal, one atom per unit cell) [66Kan]. This phase is unstable at room temperature. The decomposition to the equilibrium phases takes place over the temperature range -100 to -40 C [66Kan]. Splat- cooled alloys with higher Ag concentrations (more than 20 at.%) do not seem to show the presence of any metastable phase [68Sri]. Supersaturated (Ag) solid solutions with up to 13 at.% Sn are reported to have been obtained by rapidly quenching the liquid [63Kle, 82Zho]. 1897Hey: C.T. Heycock and F.H. Neville, Philos. Trans. R. Soc. (London) A, 189, 25-69 (1897). 07Pet: G.J. Petrenko, Z. Anorg. Chem., 53, 200-211 (1907) in German. 26Mur: A.J. Murphy, J. Inst. Met., 35, 107-129 (1926). 34Han: D. Hanson, E.J. Stanford, and H. Stevens, J. Inst. Met., 55, 115-133 ( 1934). 34Hum: W. Hume-Rothery, G.W. Mabbot, and K.M. Channel-Evans, Philos. Trans. R. Soc. (London) A, 233, 1-97 (1934). 37Hum: W. Hume-Rothery and P.W. Reynolds, Proc. R. Soc. (London) A, 160, 282- 303 (1937). 39Owe: A.E. Owen and E.W. Roberts, Philos. Mag., 27, 294-327 (1939). 40Uma: M.M. Umansky, Zh. Fiz. Khim., 14, 846-849 (1940) in Russian. 63Kle: W. Klement, Jr., and M.L. Luo, NASA Accession No. N64-31289, Rept. No. AD403779 (1963). 66Kan: R.H. Kane, B.C. Giessen, and N.J. Grant, Acta Metall., 14, 605-609 ( 1966). 68Sri: P.K. Srivastava, B.C. Giessen, and N.J. Grant, Acta Metall., 16, 1199- 1208 (1968). 72Fai: C.W. Fairhust and J.B. Cohen, Acta Crystallogr. B, 28, 371-378 (1972). 81Vnu: F. Vnuk, M.H. Ainsley, and R.W. Smith, J. Mater. Sci., 16, 1171-1176 ( 1981). 82Zho: X. Zhou, J. Jin, Y. Ning, and Z. Zhao, Acta Metall. Sinica, 18, 534-539 (1982) in Chinese. Published in Bull. Alloy Phase Diagrams, 8(4), Aug 1987. Complete evaluation contains 6 figures, 4 tables, and 51 references. Special Points of the Ag-Sn System