Фазовая диаграмма системы Au-Sn

К оглавлению: Другие диаграммы (Others phase diargams)

Au-Sn (Gold-Tin) H. Okamoto and T.B. Massalski The equilibrium phases of the Au-Sn system are (1) the liquid, L; (2) the fcc solid solution, (Au), having about 6.8 at.% solid solubility of Sn in (Au); (3) the bct terminal solid solution, (bSn), having about 0.2 at.% solid solubility of Au in (bSn); (4) the diamond-cubic type terminal solid solution, (aSn), having a very limited (<0.006 at.%) solid solubility of Au in (aSn); (5) the TiNi3-type b phase intermetallic compound Au10Sn; (6) the cph z phase solid solution, with homogeneity ranging between 10 and 18.5 at.% Sn; (7) the orthorhombic z› phase intermetallic compound Au5Sn; (8) the hexagonal NiAs- type d phase intermetallic compound, showing a small homogeneity range between 50.0 and 50.5 at.% Sn; (9) the orthorhombic e phase intermetallic compound AuSn2; and (10) the PtSn4-type orthorhombic h phase intermetallic compound AuSn4. The present evaluation of the Au-Sn system updates the phase diagram of [05Vog] , which was generally accepted by [Hansen]. It is based primarily on a review of the work of [45Owe], [59Sch], [74Osa], and [81Hay]. A single-phase metastable alloy has been made by rapidly quenching a 92 at.% Sn liquid. This phase remained undecomposed if held at the substrate temperature of about -190 C. The crystal structure is HgSn10-type hexagonal. Following splat cooling of liquid alloys on substrates at either 20 or -190 C, [68Gie] reported that a g brass-type metastable phase at about 20.5 at.% Sn coexists with z and d. Other metastable phases of undetermined structure were found in alloys within the range of 25 to 31 at.% Sn [68Gie]. A series of amorphous alloys were produced by vapor deposition on substrates held at 77 K, or below, for the composition range between 20 and 90 at.% Sn [ 79Bla]. According to differential scanning calorimetry [87Leg], b and z phases form by peritectic reactions at 532 and 519 C, respectively. 05Vog: R. Vogel, Z. Anorg. Allg. Chem., 46, 60-75 (1905) in German. 45Owe: E.A. Owen and E.A.O. Roberts, J. Inst. Met., 71, 213-254 (1945). 59Sch: K. Schubert, H. Breimer, and R. Gohle, Z. Metallkd., 50(3), 146-153 ( 1959) in German. 68Gie: B.C. Giessen, Z. Metallkd., 59(10), 805-809 (1968). 74Osa: K. Osada, S. Yamaguchi, and M. Hirabayashi, Trans. Jpn. Inst. Met., 15( 4), 256-260 (1974). 79Bla: E. Blasberg, D. Korn, and H. Pfeifle, J. Phys. F, Met. Phys., 9(9), 1821-1832 (1979). 81Hay: E. Hayer, K.L. Komarek, J.P. Bros, and M. Gaune-Escard, Z. Metallkd., 72(2), 109-115 (1981). 87Leg: B. Legendre, H.C. Chhay, F. Hayes, C.A. Maxwell, D.S. Evans, and A. Prince, Mater. Sci. Technol., 3, 875-876 (1987). This updates the evaluation published in Phase Diagrams of Binary Gold Alloys, 1987, and Bull. Alloy Phase Diagrams, 5(5), Oct 1984. Complete evaluation contains 4 figures, 6 tables, and 150 references. 1