Фазовая диаграмма системы Ag-O

К оглавлению: Другие диаграммы (Others phase diargams)

Ag-O (Silver-Oxygen) I. Karakaya and W.T. Thompson The assessed phase diagram (partial) for the Ag-O system at atmospheric pressure is superficially similar to that shown in [Hansen]. The slightly higher O solubility in the solid Ag-rich phase reported here is based on the more recent work of [62Eic], [64Pod], and [72Ram]. The data of [09Sie], [10Don] , [65Dia], [65Par], and [68Lup] were reviewed. An attempt was made to calculate this system at higher pressures. Unfortunately, at about five times higher than atmospheric pressure, deviations from the experimental data [68Bak] were observed. The assumption that the gas phase can be treated as an ideal mixture of diatomic oxygen and monatomic Ag becomes less valid as the pressure is raised, but it is noteworthy that the calculated (Ag) liquidus is closer to [68Kna]. More complicated thermodynamic models were considered unjustifiable in view of the insufficiency of experimental data. The solubility of O in liquid Ag shown in the assessed diagram emphasizes the work of [67Sha]. In locating the solubility of O in solid Ag, emphasis was placed on the work of [62Eic]. The existence of Ag2O and AgO has been established [58Gra]. Ag2O, which is the most extensively studied oxide, dissociates to solid Ag and O2 gas at temperatures above 190 C under atmospheric pressure [Hansen]. The uncertainties surrounding the existence and properties of the higher oxides have yet to be resolved. The two-phase region labeled L + G in the assessed diagram is sensitive to pressure. Higher pressures increase the O solubility in the Ag-rich liquid phase. 09Sie: A. Sieverts and J. Hagenacker, Z. Phys. Chem., 68, 115-128 (1909) in German. 10Don: F.G. Donnon and T.W.A. Shaw, J. Soc. Chem. Ind., 29, 987-989 (1910). 58Gra: W.S. Graff and H.H. Stadelmaier, J. Electrochem. Soc., 105, 446-449 ( 1958). 62Eic: W. Eichenauer and G. Muller, Z. Metallkd., 53, 321-324 and 700 ( correction) (1962) in German. 62Pal: T. Palagyi and I. Naray-Szabo, Acta Chim. Hung., 30, 1-9 (1962) in German. 64Pod: H.H. Podgurski and F.N. Davis, Trans. AIME, 230, 731-735 (1964). 65Dia: C. Diaz, C.R. Masson, and F.D. Richardson, Trans. Inst. Min. Metall., 75, C183-185 (1965). 65Par: N.A.D. Parlee and E.M. Sacris, Trans. AIME, 233, 1918-1919 (1965). 67Sha: I.D. Shah and N.A.D. Parlee, Trans. AIME, 239, 763-764 (1967). 68Bak: E.H. Baker and M.I. Talukdar, Trans. Inst. Min. Metall., 79 C, 128-133 ( 1968). 68Kna: O. Knacke and M. Meixner, Z. Metallkd., 59, 114-117 (1968) in German. 68Lup: C.H.P. Lupis and J.F. Elliott, Trans. AIME, 242, 929-935 (1968). 72Ram: T.A. Ramanarayanan and R.A. Rapp, Metall. Trans., 3, 3239-3246 (1972). Submitted to the APD Program. Complete evaluation contains 3 figures, 4 tables, and 45 references. 1