Фазовая диаграмма системы Pb-Sn

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Pb-Sn (Lead-Tin) I. Karakaya and W.T. Thompson Although the Pb-Sn system has been studied extensively, placement of the phase boundaries involves more uncertainty than might be expected for such a low melting alloy. The assessed phase diagram for the Pb-Sn system is superficially similar to that shown in [Hansen], but is based entirely on thermodynamic calculations and review of the experimental data [1890Hey, 1892Hey, 1894Wie, 01Cha, 01Kap, 07Sto, 08Ros]. Because of the small composition range for the Sn liquidus (73.9 to 100 at.% Sn), restricted Pb solubility in the (bSn) phase (1.3 at.% maximum), and small positive enthalpy of mixing for the liquid, the calculated Sn liquidus is very certain. Experimental data [1890Hey, 01Cha, 07Sto, 21Kon, 79Tok] support this, and the findings of [1892Hey], [01Cha], and [07Sto] were included in placing the Pb liquidus. From the thermodynamic/phase diagram optimization, the calculated eutectic composition at 183 C is 28.1 at.% Pb, in agreement with [ Hansen]. The solidus and solvus compositions reported for the (Pb) phase show much scatter, which, for the solvus, is due to very slow and two-stage precipitation of Sn from the (Pb) phase [60Cah], as deduced from kinetic [ 55Tur, 56Des, 58Tur] and thermodynamic [58Mur] studies. In the assessment of the Pb solidus, importance was given to the electrical resistivity measurements of [49Hul]. The maximum solubility of Sn in (Pb) at the eutectic (183 C), 28.1 at.%, is consistent with previous evaluations [47Ray, 81Nga, Hansen]. Differential thermal analysis [69Ton] and X-ray [82Deg] studies of Pb-Sn alloys at very high pressures (over 1250 MPa) revealed the presence of phases not observed at standard atmospheric pressure. This should not be surprising, because pure Sn undergoes an allotropic change to fcc at 3200 MPa [63Kau]. The disappearance of the simple eutectic nature of the phase diagram at pressures above 1800 MPa [71Oza] is associated with the appearance of the e phase. 1890Hey: C.T. Heycock and F.H. Neville, J. Chem. Soc., 57, 376-393 (1890). 1892Hey: C.T. Heycock and F.H. Neville, J. Chem. Soc., 61, 888-916 (1892). 1894Wie: B. Wiesengrund, Wied. Ann., 52, 777 (1894); as cited in [09Deg]. 01Cha: G. Charpy, Contr. Etud. Alliages (1901); as cited in [09Deg]. 01Kap: A.W. Kapp, Ann. Phys., 6, 754 (1901); as cited in [09Deg]. 07Sto: A. Stofel, Z. Anorg. Allg. Chem., 53, 137-155 (1907) in German. 08Ros: W. Rosenhain and P.A. Tucker, Philos. Trans. R. Soc. (London)., 209, 89- 122 (1908). 09Deg: P.N. Degens, Z. Anorg. Chem., 63, 207-224 (1909) in German. 21Kon: S. Konno, Sci. Rep. T“hoku Imp. Univ., 10, 57-74 (1921). 47Ray: G.V. Raynor, Annotated Equilibrium Diagrams, No. 6, The Institute of Metals, London (1947). 49Hul: R. Hultgren and S.A. Lever, Trans. AIME, 185, 67-71 (1949). 54Lee: J.A. Lee and G.V. Raynor, Proc. Phys. Soc., 67, 737-747 (1954). 54Tyz: C. Tyzack and G.V. Raynor, Acta Crystallogr., 7, 505-510 (1954). 55Tur: D. Turnbull and H.N. Treaftis, Acta Metall., 3, 43-54 (1955). 56Des: W. DeSorbo and D. Turnbull, Acta Metall., 4, 495-509 (1956). 58Mur: W.K. Murphy and R.A. Oriani, Acta Metall., 6, 556 (1958). 58Tur: D. Turnbull and H.N. Treaftis, Trans. AIME, 212, 33-39 (1958). 60Cah: J.W. Cahn and H.N. Treaftis, Trans. AIME, 218, 376-377 (1960). 63Kau: L. Kaufman, Solids Under Pressure, McGraw-Hill, New York (1963). 68Yok: O.O. Yokunin and V.I. Tkach, Ukr. Fiz. Zh., 13, 326-328 (1968) in Russian. 69Ton: E.Y. Tonkov and I.L. Aptebar, Dokl. Akad. Nauk SSR, 188, 401-402 (1969) in Russian. 71Oza: Y. Ozaki and S. Saito, Jpn. J. Appl. Phys., 10, 149-153 (1971). 74Sar: P.R. Sarode and A.R. Chetal, Current Sci., 43, 339 (1974). 79Tok: V.S. Tokmakov, Y.V. Moish, Y.S. Astashkim, LY.V. Silanov, and V.V. Zhiryakov, Zavod. Lab., 45, 26-28 (1979) in Russian. 81Nga: T.L. Ngai and Y.A. Chang, Calphad, 5, 267-276 (1981). 82Deg: V.F. Degtyareva and E.G. Ponyatovski, Fiz. Tverd. Tela, 24, 2672-2681 ( 1982) in Russian. Published in Bull. Alloy Phase Diagrams, 9(2), Apr 1988. Complete evaluation contains 6 figures, 4 tables, and 61 references. 1