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1.
E. A. Luk’yanova L. L. Rokhlin T. V. Dobatkina I. G. Korol’kova 《Russian Metallurgy (Metally)》2011,(5):484-490
Differential thermal, electron microprobe, and X-ray diffraction analyses and metallography are used to study Mg-Sm-Tb alloys containing up to 30% Sm or Tb. Polythermal sections and the solidification surface of the Mg-Sm-Tb phase diagram are constructed for the Mg-rich region. In the composition range under study, nonvariant transition-type equilibrium L + Mg24Tb5 = (Mg) + Mg41Sm5 is found to exist at a temperature of 539°C. 相似文献
2.
Jafar Safarian Leiv Kolbeinsen Merete Tangstad 《Metallurgical and Materials Transactions B》2011,42(4):852-874
Thermodynamic knowledge about liquid silicon is crucial for the production of solar-grade silicon feedstock from molten silicon.
In the current study, liquidus for silicon binary alloys is formulated using a previously developed method in which the liquidus
curve is calculated using two constants. The liquidus measurements for the silicon portion of the silicon alloys with Al,
Ca, Mg, Fe, Ti, Zn, Cu, Ag, Au, Pt, Sn, Pb, Bi, Sb, Ga, In, Ni, Pd, Mn, and Rh are reviewed, and the consistent data were
used to determine the liquidus constants. The liquidus curves for silicon binary systems are calculated and plotted. It is
indicated that the calculated liquidus curves fit well with the experimental data. A correlation between the determined liquidus
constants is also observed, which can be used to gain a better understanding of the thermodynamics of the silicon binary melts. 相似文献
3.
C. D. Anderson W. H. Hofmeister R. J. Bayuzick 《Metallurgical and Materials Transactions A》1993,24(1):61-66
Liquidus temperatures were determined for the titanium-aluminum system at compositions ranging from 41 to 62 at. pct Al. The
measurements were obtained by inducing solidification of slightly undercooled melts under containerless processing conditions
using electromagnetic levitation. Absolute temperatures were determined by optical pyrometry in combination with independent
measurements of spectral emissivities by laser polarimetry. The present liquidus temperatures are in agreement with two sets
of literature values and are consistent with a set of solid-state literature data. These values exceed those selected in one
recent proposed phase diagram revision by about 30 K and are as much as 40 to 60 K higher than those in another proposed revision.
Formerly Ph.D. Candidate, Department of Materials Science and Engineering, Vanderbilt University 相似文献
4.
Asbjørn Solheim 《Metallurgical and Materials Transactions B》2012,43(4):995-1000
The electrolyte in Hall-Héroult cells for the manufacture of primary aluminum nominally contains only cryolite (Na3AlF6) with additions of AlF3, CaF2, and Al2O3. However, impurities are present, entering the process with the feedstock. The effect on the liquidus temperature by the impurities cannot be calculated correctly by the well-known equation for freezing-point depression in binary systems simply because the electrolyte cannot be regarded as a binary system. By extending the equation for freezing-point depression to the ternary system NaF-AlF3-B, it appeared that the acidity of the impurity B plays a major role. Some calculations were made using an ideal Temkin model, and for most types of impurities, the effect on the liquidus temperature will be larger in an industrial electrolyte than what can be estimated from the equation for freezing-point depression in cryolite. Experimental data on the liquidus temperature in the system Na3AlF6-AlF3-Al2O3-CaF2-MgF2 show that the effect of MgF2 on the liquidus temperature increases strongly with decreasing NaF/AlF3 molar ratio, and it is suggested that MgF2 forms an anion complex, probably MgF 4 2? . 相似文献
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6.
Liquidus surface and solidification scheme for alloys of the system Ti-Ni-Zr containing up to 50% Ni
V. N. Eremenko E. L. Semenova L. A. Tret'yachenko 《Powder Metallurgy and Metal Ceramics》1991,30(8):664-668
Translated from Poroshkovaya Metallurgiya, No. 8(344), pp. 49–54, August, 1991. 相似文献
7.
The liquidus surface for the Al2O3-ZrO2-Yb2O3 phase diagram is constructed for the first time. No ternary compounds are found in the system. The liquidus surface is completed by seven primary crystallization fields. Two four-phase invariant eutectic equilibria, two four-phase invariant transition equilibria, and one three-phase invariant eutectic equilibrium are found in the ternary system. Since ZrO2 interacts with other phases eutectically, composite materials can combine the unique properties of ZrO2-based T-and F-phases with the properties of other phases of the Al2O3-ZrO2-Yb2O3 system. 相似文献
8.
Jui-shen Chang Sinn-wen Chen Kuo-chun Chiu Hsin-jay Wu Jee-jay Chen 《Metallurgical and Materials Transactions A》2014,45(9):3728-3740
The Ag-Sn-Te ternary system is of interest to thermoelectric applications and its liquidus projection is determined in this study. Forty Ag-Sn-Te ternary alloys are prepared and their primary solidification phases are determined. These different primary solidification phase regions include three terminal solid solutions: Ag, Sn, and Te; six binary intermediate phases: SnTe, β-Ag5Te3, Ag1.9Te, Ag2Te (assuming no phase transformation), ζ-Ag4Sn, and ε-Ag3Sn; and one ternary compound, AgSnTe2. These data, together with the phase diagrams of the three constituent binary systems, are employed to construct the univariant lines of the liquidus projection. The temperature-descending directions of these univariant lines are determined using thermal analysis results and mass balance concept. The types of invariant reactions and the reaction temperatures are determined from the temperature-descending directions of the univariant lines and by thermal analysis. There are two Class I reactions, five Class II reactions, and one Class III reaction. The invariant reaction with the highest reaction temperature is L + Ag = Ag2Te + ε-Ag3Sn, at 992.7 ± 4 K (719.5 ± 4 °C), and that with the lowest reaction temperature is L = Sn + ε-Ag3Sn + SnTe, at 494.2 ± 4 K (221 ± 2 °C). 相似文献
9.
The liquidus temperature of steel is greatly affected by its chemical composition; therefore, the value of the liquidus temperature can vary among different types of steel. In this study, on the basis of the concept of differentiation, the Fe‐i binary phase diagram is analyzed using Photoshop image processing software. The effects of eleven common alloying elements (C, Si, Mn, P, S, Ca, Ni, Cu, Cr, Nb, and Mo, whose content is between 0%~4%) on the melting point of pure iron are analyzed. This analysis proves the following assumption to be incorrect: the relationship between the change in liquidus temperature and the content of element i is a linear relationship; this assumption is the basis of traditional liquidus calculation models. A new model for calculating the liquidus temperature of steel is established in this study. As compared to data from other literature, the model proposed in this paper has good generality and the calculation error of the liquidus temperature of steel is between ?3 and 4 °C, which is acceptable. A statistical analysis of the experimental data for different steel grades (obtained from Laiwu Special Steel) using the developed model showed that 87.2% of the absolute deviation values of the temperature are within 4 °C. This result shows the model to be both reasonable and credible. 相似文献
10.
A projection has been constructed for the liquidus surface on the plane of the concentration triangle for the Al2O3-ZrO2-Sm2O3 phase diagram. There are no ternary compounds, or appreciable regions of solid solutions based on the components and the
binary compounds. The liquidus surface is formed by nine fields of primary phase crystallization. There are five four-phase
nonvariant peritectic equilibria, as well as two four-phase nonvariant eutectic equilibria, and one three-phase nonvariant
eutectic equilibrium. As the ZrO2 and SmAlO3 phases interact with other phases by a eutectic mechanism, it is possible to combine the unique properties of the T and F
solid solutions based on ZrO2 with the properties of the other phases in the form of composites.
__________
Translated from Poroshkovaya Metallurgiya, Nos. 3–4(448), pp. 28–35, March–April, 2006. 相似文献
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Thermal analysis is often used to determine equilibrium phase boundary temperatures such as the liquids. Accurate measurements
require proper calibration procedures, which are standard for given instruments. In multicomponent alloys such as RENE N5
and PWA 1484 superalloys, a complex melting behavior associated with the solidification structure was exposed by examining
the melting response at different heating rates. The observed variability in the melting signal is related to the sample processing
history and is not addressed by the various standard calibration methods or supplemental procedures for different heating
rates. The liquidus temperature can be determined under conditions approaching full compositional equilibrium by the application
of an interrupted-heating thermal analysis protocol. The approach provides a new strategy for the reliable determination of
phase boundary temperatures by thermal analysis. 相似文献
13.
Sinn-Wen Chen Jui-Shen Chang Kevin Pan Chia-Ming Hsu Che-Wei Hsu 《Metallurgical and Materials Transactions A》2013,44(4):1656-1664
This study investigates the Sn-Co-Cu ternary system, which is of interest to the electronics industry. Ternary Sn-Co-Cu alloys were prepared, their as-solidified microstructures were examined, and their primary solidification phases were determined. The primary solidification phases observed were Cu, Co, Co3Sn2, CoSn, CoSn2, Cu6Sn5, Co3Sn2, γ, and β phases. Although there are ternary compounds reported in this ternary system, no ternary compound was found as the primary solidification phase. The directional solidification technique was applied when difficulties were encountered using the conventional quenching method to distinguish the primary solidification phases, such as Cu6Sn5, Cu3Sn, and γ phases. Of all the primary solidification phases, the Co3Sn2 and Co phases have the largest compositional regimes in which alloys display them as the primary solidification phases. There are four class II reactions and four class III reactions. The reactions with the highest and lowest reaction temperatures are both class III reactions, and are L + CoSn2 + Cu6Sn5 = CoSn3 at 621.5 K (348.3 °C) and L + Co3Sn2 + CoSn = Cu6Sn5 at 1157.8 K (884.6 °C), respectively. 相似文献
14.
Alexei Apisarov Alexander Dedyukhin Elena Nikolaeva Pavel Tinghaev Olga Tkacheva Alexander Redkin Yurii Zaikov 《Metallurgical and Materials Transactions B》2011,42(1):236-242
The effect of calcium fluoride on liquidus temperatures of the cryolite melts with a low cryolite ratio (CR) was studied.
The systems KF-NaF-AlF3 and KF-LiF-AlF3 with CRs of 1.3, 1.5, and 1.7 have been investigated. The liquidus curves of systems containing CaF2 are different and depend on the K/(K + Na) and K/(K + Li) ratios. In potassium cryolite with CRs of 1.3 and 1.5, the calcium
fluoride solubility is low and increases with NaF (LiF) concentration. 相似文献
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16.
Chih-hao Liu Hsin-jay Wu Sinn-wen Chen 《Metallurgical and Materials Transactions A》2013,44(12):5424-5433
The ternary Bi-Sb-Te system is important for thermoelectric applications. Its liquidus projection is determined, except for the Bi-rich corner with various unconfirmed binary Bi-Te compounds. Fifty Bi-Sb-Te ternary alloys are prepared. Primary solidification phases are identified using metallographic observations and X-ray diffraction techniques. Phase transformation temperatures are determined using differential thermal analysis. No ternary compound is found. (Bi,Sb)2Te3 and (Bi,Sb) are continuous solid solutions. The Bi2Te3 and Sb2Te3 phases form a pseudo-binary section. Alloys of the primary solidification phases of Te, (Bi,Sb)2Te3, γ, δ, and (Bi,Sb) are determined and the boundaries of various primary solidification phases are delineated. The Bi-Sb-Te liquidus projection is also calculated with the CALPHAD method using preliminary thermodynamic models, and the calculated results are qualitatively in agreement with the experimental determinations. 相似文献
17.
介绍半固态铝合金的各种制备工艺,分析了近液相线半连续铸造法制备半固态铝合金的现状与发展趋势,探讨半固态初生球状晶形成机理的研究现状,指出近液相线半连续铸造法具有广阔的应用前景。 相似文献
18.
Metallurgical and Materials Transactions B - Phase equilibria of the ternary CaO-ZnO-SiO2 system have been investigated at 1170 °C to 1691 °C for oxide liquid in equilibrium... 相似文献
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20.
Marta Dias Patr��cia Almeida Carvalho Marcel Bohn Olivier Tougait Henri No?l Ant��nio Pereira Gon?alves 《Metallurgical and Materials Transactions A》2013,44(1):395-405
The liquidus projection at the boron-rich corner of the B-Fe-U phase diagram is proposed based on powder X-ray diffraction measurements, heating curves, and scanning electron microscopy observations, complemented with both energy dispersive X-ray spectroscopy and electron probe microanalysis. Evidence for six ternary reactions is presented, the corresponding 12 monovariant lines are drawn, and the nature and location of the ternary reactions are given. The ternary compounds existing in this region of the B-Fe-U ternary phase diagram, UFeB4 and UFe2B6, were confirmed to be formed by ternary peritectic reactions, yet UFeB4 has a considerably larger primary crystallization field, which points to an easier preparation of single crystals of this compound, when compared with UFe2B6. 相似文献