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1.
The Bi-MnBi eutectic region of the Bi-Mn phase diagram 总被引:3,自引:0,他引:3
Ron G. Pirich G. Busch W. Poit D. J. Larson 《Metallurgical and Materials Transactions A》1980,11(1):193-194
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A. K. Shurin G. P. Dmitrieva N. A. Razumova É. L. Khandros 《Powder Metallurgy and Metal Ceramics》1987,26(8):658-660
Conclusions The Ni-VC0.87-NbC0.9 system has a ternary eutectic in the solidification of which the equilibrium phases are an Ni-base solid solution, (V, Nb)C carbide containing 10% NbC0.9 and 90% VC0.87, and (V, Nb)C carbide containing 20% VC0.87 and 80% NbC0.9. The point of the four-phase nonvariant equilibrium is in the region of the alloy containing 3% NbC0.9 and 6% VC0.87 and the temperature of the equilibrium is 1300±15°C. The diagram of the phase equilibria (Fig. 3) of this system has the same form as for the Ni-TiC-ZrC and Ni-TiC-HfC systems [9, 10].Translated from Poroshkovaya Metallurgiya, No. 8(296), pp. 67–79, August, 1987. 相似文献
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The Ag-Au-Si system: Experimental and calculated phase diagram 总被引:7,自引:0,他引:7
S. Hassam J. Ägren M. Gaune-escard J. P. Bros 《Metallurgical and Materials Transactions A》1990,21(7):1877-1884
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The change in mass and composition of the phases during the equilibrium solidification of eutectic alloys in three-component systems is considered. For the model system A-B-C, we show that equilibrium solidification of binary eutectics in three-component systems is determined by processes of decomposition and interaction, as in the crystallization of a solid solution. Eutectic transformation is generally associated with equilibrium solidification, since decomposition dominates over interaction. These findings are confirmed by studying solidification in the Al-Si-Cu system. 相似文献
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V. N. Eremenko V. G. Khoruzhaya T. D. Shtepa L. S. Kriklya 《Powder Metallurgy and Metal Ceramics》1992,31(2):157-161
Translated from Poroshkovaya Metallurgiya, No. 2(350), pp. 68–73, February, 1992. 相似文献
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A solidification model is developed and experimentally checked for Fe-C-Cr-Nb alloys in the white cast irons range. It is
based on a partial quaternary Fe-C-Cr-NbC phase diagram and predicts the possible solidification paths for the alloys containing
γ, with (Fe,Cr)7C3 and NbC as the microconstituents at room temperature. The dendritic γ to massive (Fe,Cr)7C3 transition in experimental alloy microstructures with NbC contents up to 22 pet is explained by this model. Thermal analysis
is also used to compare the solidification paths and model approach. 相似文献
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A Gaussian plus Krupkowski formalism is used to represent the phase diagram, boiling point data, and the thermodynamic properties
of the zinc-lead system. The high shear technique of Esdaile and Siviour 1 was adapted for measurements of the monotectic
conditions and the boundaries of the liquid miscibility gap. The monotectic conditions were found to be 690.94 ± 0.02 K and
1.017 ± 0.005 wt pct Pb, 0.323 ± 0.002 at. pct Pb. 相似文献
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Thermodynamics and phase diagram of the Fe-C system 总被引:1,自引:0,他引:1
John Chipman 《Metallurgical and Materials Transactions B》1972,3(1):55-64
A critical review of published data provides a fairly accurate knowledge of the thermodynamic properties of all of the phases
of the system Fe-C that are stable or metastable at atmospheric pressure. Selected data are shown as tables and equations.
A proposed phase diagram differs only slightly from others recently published but has the following features. Peritectic compositions
and the α-γ equilibrium are shown to agree with measured values of the activity of iron in the solid and liquid solutions
and the thermodynamic properties of pure iron. Of all the reported carbides of iron only two may be studied under equilibrium
conditions. The solubilities of cementite and of χ-carbide in α-Fe are deduced from measured equilibria. Both are metastable
at all temperatures with respect to graphite and its saturated solution in iron. The χ-carbide becomes more stable than cementite
below about 230° Certain published data on ε-carbide permit an estimate of its free energy as a precipitate during the aging
process. 相似文献
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In order to provide the necessary phase equilibria data for understanding the development of the Widmanstatten pattern in
iron meteorites, we have redetermined the Fe-Ni-P phase diagram from 0 to 100 pct Ni, 0 to 16.5 wt pct P, in the temperature
range 1100° to 550°C. Long term heat treatments and 130 selected alloys were used. The electron microprobe was employed to
measure the composition of the coexisting phases directly. We found that the fourphase reaction isotherm, where α+ liq ⇌ γ+ Ph, occurs at 1000° ± 5°C. Above this temperature the ternary fields α+ Ph + liq and α+ γ+ liq are stable and below 1000°C, the ternary fields ⇌+ γ + Ph and γ + Ph + liq are stable. Below 875°C a eutectic reaction, liq → γ + Ph, occurs at the Ni-P edge of the diagram.
Altogether nineteen isotherms were determined in this study. The phase boundary compositions of the two-and three-phase fields
are listed and are compared with the three binary diagrams. The α + γ + Ph field expands in area in each isotherm as the temperature
decreases from 1000°C. Below 800°C the nickel content in all three phases increases with decreasing temperature. The phosphorus
solubility in α and γ decreases from 2.7 and 1.4 wt pct at 1000°C to 0.25 and 0.08 wt pct at 550°C. The addition of phosphorus
to binary Fe-Ni greatly affects the α/α + γ and γ/α + γ boundaries below 900°C. It stabilizes the α phase by increasing the
solubility of nickel (α/α +γ boundary) and above 700°C, it decreases the stability field of the γ phase by decreasing the
solubility of nickel(@#@ γ/α + γ boundary). However below 700°C, phosphorus reverses its role in γ and acts as a γ stabilizer, increasing the nickel
solubility range. The addition of phosphorus to Fe-Ni caused significant changes in the nucleation and growth processes. Phosphorus
contents of 0.1 wt pct or more allow the direct precipitation ofa from the parent γ phase by the reaction γ ⇌ α + γ. The growth rate of the α phase is substantially higher than that predicted
from the binary diffusion coefficients.
Formerly at Planetology Branch, Goddard Space Flight Center 相似文献
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Thermodynamic studies and the phase diagram of the Li-Mg system 总被引:1,自引:0,他引:1
W. Gasior Z. Moser W. Zakulski G. Schwitzgebel 《Metallurgical and Materials Transactions A》1996,27(9):2419-2428
By means of the electromotive force (emf) method of concentration cells of the following scheme: Li (1) / LiCl-LiF (eut) or
LiCi-KCl (eut) / Li-Mg (1) or Li (1) / LiCl-LiF (eut) / Li-Mg (s) Li activities for liquid and solid alloys at the (Mg), (Li),
and (Mg) + (Li) two-phase region of the Li-Mg system were determined. Liquid alloys were examined at temperatures from 638
to 889 K at various Li concentrations. The (Mg) solid solutions were investigated in two series: at constant temperatures
between 773 and 876 K, with varying Li content, and at fixed Li concentrations, equal to 0.125 and 0.160 molar fractions,
at different temperatures between 772 and 849 K. At the two-phase region, (Mg) + (Li), emf measurements were performed in
the temperature range 773 to 838 K, with fixed Li concentrations equal to 0.20, 0.25, and 0.275 molar fractions. For (Li)
solid alloys, experiments were done at temperatures 773 to 849 K for several constant Li concentrations, between 0.30 to 0.45
molar fractions, respectively. Studies on solid alloys enabled us also to determine the boundaries (Li)/[(Mg) + (Li)] and
(Mg)/[(Mg) + (Li)] at temperatures 773 to 831 K. The resulting thermodynamic and phase boundary data of this study were used
with other selected references for a critical assessment of the Li-Mg system. The Lukas BINGSS optimization program and BINFKT
for the calculation of the thermodynamic functions and of the phase diagram were used. The calculated equilibrium phase diagram
at temperatures below 750 K indicates a slightly lower solid solubility of Mg in (Li) in comparison with results from thermal
analysis and the recently published Saunders evaluation. 相似文献
19.
Zbigniew Moser Wojciech Zakulski Zdziseaw Panek Marian Kucharski Leszek Zabdyr 《Metallurgical and Materials Transactions B》1990,21(4):707-714
By means of concentration cells of the following type, Mg (l)MgCl2 in (LiCl-KCl)eut (l)Mg-Sn (1), the partial thermodynamic data of Mg in Mg-Sn liquid solutions have been obtained in the composition range
of 0.1 ≤X
Mg ≤ 0.75 and at temperatures from 950 to 1100 K. These values are compared with thermodynamic data reported in the literature
and used for the evaluation to obtain a complete set of thermodynamic functions for phase diagram calculations and for further
interpretation by the associate model. This model, which accepts the existence of ‘Mg2Sn as-sociates’ in the liquid alloys, enables calculations of viscosity by Kucharski’s method corre-lating properly with experimental
data. Mutual correlations between thermodynamic properties, physical properties, structure, and the phase diagram of the Mg-Sn
system were shown to in-dicate a maximum chemical short-range order close to the composition Mg2Sn. 相似文献