Фазовая диаграмма системы Ni-O

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Ni-O (Nickel-Oxygen) J.P. Neumann, T. Zhong, and Y.A. Chang The Ni-O phase diagram has been studied only in the composition range from Ni to NiO (b). The assessed partial diagram is taken from [Hansen] and [Metals]. The liquidus in Ni-rich melts is based on measurements by [82Con]. The solubility of oxygen in liquid Ni was found to be lower in Al2O3 crucibles than in NiO crucibles [61Bow]. Extrapolating the solubility data at higher temperatures to the eutectic point at 1713 K, an oxygen concentration of about 0.9 at.% O is obtained. No determinations of the liquidus curve above 2000 K have been reported. In addition to the condensed solid and liquid phases, a gas phase, oxygen, also exists. For a complete description of the system, it is therefore necessary to specify for each composition and temperature of the condensed phases the corresponding equilibrium pressure of oxygen in the gas phase. This is done partially in the diagram showing the Ni-rich region by indicating some isobars corresponding to oxygen pressures of log (PO2 /bar) = -5 and -4. The solubility of oxygen in solid Ni below the eutectic temperature is approximately XO = 5 C 10-4 (0.05 at.% O) [Metals]. Thermodynamic data are available for the equilibria Ni + NiO(HT) and Ni(L) + NiO(HT). [76Mah] selected thermodynamic studies based on the use of oxygen pressure as a function of temperature. Good agreement was found with the phase diagram. 61Bow: J.W. Bowers, J. Inst. Met., 90, 321-328 (1961-1962). 76Mah: A.D. Mah and L.B. Pankratz U.S. Bur. Mines Bull., 668 (1976). 82Con: B.R. Conrad, INCO Metals Company, Sheridan Park, Mississauga, Ontario, private communication (1982). Published in Phase Diagrams of Binary Nickel Alloys, 1991, and Bull. Alloy Phase Diagrams, 5(4), Aug 1984. Complete evaluation contains 2 figures, 1 table, and 33 references. 1