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Adding titanium oxide has become a common practice in modern blast furnace operating procedures. The blast furnace slag is based on the CaO–MgO–Al 2 O 3 –SiO 2 –TiO 2 low titanium slag system rather than CaO–MgO–Al 2 O 3 –SiO 2 system. Phase equilibria in the CaO–SiO 2 –Al 2 O 3 –MgO–TiO 2 system in the low-TiO 2 part have been experimentally determined by means of high temperature equilibration and quenching technique followed by electron probe X-ray microanalysis. Introducing a small quantity of titanium-bearing materials can lower the liquidus temperature. The TiO 2 content in the slag should be controlled below 4.6 wt%, otherwise it will enter the perovskite phase region where the liquidus temperatures increases rapidly. The compositions of the solid solutions corresponding to the liquidus have been precisely measured and should be utilized for developing the thermodynamic database. [ABSTRACT FROM AUTHOR]

The Ho-Bi-Te ternary system was studied by DTA, X-ray diffraction, and MSA, as well as by measuring microhardness and determining density, congruent triangulation scheme and projection of the liquidus surface, types and coordinates of mono- and invariant equilibria. It is established that this system is triangulated into five pseudo-ternary systems. It was discovered that an incongruently melting ternary compound containing HoBiTe3 is formed in the Ho-Bi-Te ternary system. X-ray phase analysis established that the HoBiTe3 compound crystallises in a tetragonal system with lattice parameters: a = 19.99, с = 13.82 Å, Z = 3. Studying the nature of the interaction of the components of the quasi-binary section Bi2Te3-Ho2Te3 of the Ho-Bi-Te ternary system, as well as thermoelectric materials formed by combining Bi2Te3 with rare-earth tellurides, is of interest from a scientific and practical point of view. [ABSTRACT FROM AUTHOR]

Complex methods of physical and chemical analysis: differential thermal analysis (DTA), X-ray phase analysis (XRD), microstructural analysis (MSA), as well as density and microhardness measurements, were used to study the nature of chemical interaction in the Ho-Sb-Te ternary system over the entire concentration range along the following sections:1. Sb2Te3-Ho2Te3, 2. Sb2Te3-HoTe, 3. HoTe-Sb, 4. HoSb-HoTe, 5. Sb2Te3-Ho, 6. HoSb-Te. The projection of the liquidus surface of the ternary system and the diagrams of the state of internal sections were constructed according to experimental data and literature data on binary systems: Sb-Te, Sb-Ho, Ho-Te. It is established that sections (1), (2), (3), (4) are quasi-binary, and (5), (6) are non-quasi-binary sections of the ternary system. The incongruently melting compound HoSbTe3 is formed in the Sb2Te3-Ho2Te3 system and the area of solid solutions based on Sb2Te3 ~ 3‑5 mol% at 300K was found.

The variability of the composition of recycled copper-containing materials requires enhanced control and understanding of slag chemistry in the secondary pyrometallurgical processing, when compared to primary copper smelting. In the black copper route for recycling waste electronic and electrical equipment (WEEE), slags exhibit high concentrations of alumina and zinc oxide. The simplest system governing phase equilibria at the reducing smelting stage of the black copper process is "CuO 0.5 "-ZnO-FeO-FeO 1.5 -CaO-SiO 2 -AlO 1.5. In the present study, slags within this system were equilibrated with liquid copper Cu and solid Fe metallic alloys, quenched and characterized by the Electron Probe X-ray Microanalysis (EPMA). The range of compositions was selected based on the information about the process available in literature. The study focused on the liquidus and proportion of solid spinel in the temperature range from 1100 to 1300 °C. Precise control of the proportion of solids can enhance the stability of refractory materials against corrosive slags while maintaining entrained metal droplets at reasonably low level. Additionally, experimental correlations between the solubility of copper in the oxide liquid and the partial pressure of oxygen were developed for the Zn-free slags in equilibrium with metallic copper at 1200 and 1300 °C. All experimental results were compared to thermodynamic predictions using recent models and FactSage® software. Uncertainties were identified to be used in further model improvement. [ABSTRACT FROM AUTHOR]

Complex methods of physical and chemical analysis: differential thermal analysis (DTA), X-ray phase analysis (XRD), microstructural analysis (MSA), as well as density and microhardness measurements, were used to study the nature of chemical interaction in the Ho-Sb-Te ternary system over the entire concentration range along the following sections:1. Sb2Te3-Ho2Te3, 2. Sb2Te3-HoTe, 3. HoTe-Sb, 4. HoSb-HoTe, 5. Sb2Te3-Ho, 6. HoSb-Te. The projection of the liquidus surface of the ternary system and the diagrams of the state of internal sections were constructed according to experimental data and literature data on binary systems: Sb-Te, Sb-Ho, Ho-Te. It is established that sections (1), (2), (3), (4) are quasi-binary, and (5), (6) are non-quasi-binary sections of the ternary system. The incongruently melting compound HoSbTe3 is formed in the Sb2Te3-Ho2Te3 system and the area of solid solutions based on Sb2Te3 ~ 3-5 mol% at 300K was found. [ABSTRACT FROM AUTHOR]

An integrated experimental and thermodynamic modeling investigation of the phase equilibria in the PbO–NiO–SiO2 system in air and also in equilibrium with liquid metal has been undertaken to better characterize the chemical reactions taking place in the Ni‐containing Pb processing slags. New experimental phase equilibria data at 720°C–1740°C were obtained for this system using high‐temperature equilibration of synthetic mixtures with predetermined compositions in sealed silica ampoules or in Au/Pt–Ir foils, a rapid quenching technique, and electron probe x‐ray microanalysis of the equilibrated phase compositions. Phase equilibria and liquidus isotherms in the quartz/tridymite/cristobalite (SiO2), olivine (Ni2SiO4), monoxide (NiO), Ni‐barysilite (Pb8NiSi6O21), massicot (PbO), and di‐lead silicate (Pb2SiO4) primary phase fields were revealed and the extent of the high‐SiO2 two‐liquid immiscibility gap in equilibrium with cristobalite was determined. New experimental data were used in the development of a thermodynamic database describing this ternary system. Also, modeling revision of the NiO–SiO2 binary system was conducted, resulting in a smaller miscibility gap in ternary systems that was closer to the experimental results. [ABSTRACT FROM AUTHOR]

Using the analytical option of the Origin Lab computer program, the analytical dependences of the liquidus temperature on the composition for the PbTe-Bi2Te3, PbTe-Sb2Te3, Bi2Te3-Sb2Te3 boundary systems of the PbTe-Bi2Te3-Sb2Te3 ternary system were determined. Based on these dependencies and thermal analysis data of the ternary system, the analytical model of the temperature-composite dependence of the crystallization surfaces of PbTe, Sb2Te3, Bi2Te3 compounds and PbBi2Te54, PbBi54Te7, PbBi6Te10 phases in the PbTe-Bi2Te3-Sb2Te3 system was determined. The resulting equations made it possible to visualize the phase diagram of the PbTe-Bi2Te3-Sb2Te3 system from the side of the PbTe-Bi2Te3 in 3D coordinates. The analytical model of the phase diagram of the PbTe-Bi2Te3-Sb2Te3 system allowed constructing a threedimensional image of equilibrium phases from different angles, to obtain two-dimensional projections and to tabulate the coordinates of the phase diagram [ABSTRACT FROM AUTHOR]

One of the ways to improve the performance of gas-turbine engine blades is improvement the alloying complexes of heat-resistant nickel alloys used for casting. The influences of refractory metals on the macro- and microstructure and the properties of alloys of this type are analysed. It is proposed to introduce rhenium and tantalum into a heat-resistant corrosion-resistant nickel alloy for the production of working blades of gas-turbine engines. The paper presents the results of the study of the influence of chemical composition on the phase--structural components of heat-resistant alloy. Phase-transition temperatures for a new heat-resistant corrosion-resistant nickel alloy containing rhenium and tantalum have been established: liquidus temperature is of = 1370°C, solidus temperature is of 1320°C. Studies of the microstructure of the obtained samples in the cast state, after heating and cooling in calorimetric studies, make it possible to confirm that the phase--structural state corresponds to the alloy of this type, it consists of γ-solid solution including γ'-phase and carbides. Rhenium is mainly part of the γ-solid solution, and tantalum strengthens the cell boundaries. When analysing the structures of the studied samples after heating in a calorimeter to 1250°C, topologically close-packed phases in the alloy containing rhenium and tantalum are not formed. Comparative studies have shown that the introduction of rhenium and tantalum to alloy improves its thermophysical properties, namely, liquidus, solidus and complete-dissolution temperatures, by about 50°C higher than for the standard heat-resistant nickel alloy CM88Y. [ABSTRACT FROM AUTHOR]

Conventional converting of nickel-containing copper mattes in Peirce–Smith horizontal converters does not conform with the current environmental regulations. A global trend is to change over from conventional batch converting to a continuous converting process producing running slags. The main purpose of the continuous matte converting process is to produce commercial blister copper that would not require oxidation during further anode refining. To minimize the risks of obtaining off-grade blister copper, the Norilsk Nickel Continuous Converting of Copper Nickel-Containing Mattes Project provides for granulation and rapid determination of the composition of converter matte using an on-stream analyzer. Currently, the matte granulation process has not been studied adequately. The objective of this paper is to study the granulation of copper–nickel mattes of variant composition under various process conditions. The effect of the granulated matte composition on water pH has been studied. Noticeable acidification of water used for melt granulation has been found out, which is probably due to the formation of soluble sulfates of non-ferrous metals and sulfuric acid. To minimize the risk of equipment wear, a method for neutralizing the process water with alkali in the granulation unit has been proposed. The time of accumulation of sodium sulfate to the solubility limit in the closed water supply cycle of the granulation unit has been determined based on the composition of granulated mattes. DTA and TGA data for granulated matte samples indicate a decrease in the equivalent diameter of matte granules with increase in the degree of superheating above the liquidus temperature. It has been established that not only the superheating of the melt, but also the pressure head of granulation water–air jet affects the degree of dispergation of the melt. [ABSTRACT FROM AUTHOR]

Phase equilibria studies were undertaken on the "CuO 0.5 "-AlO 1.5 -SiO 2 system in equilibrium with metallic copper using equilibration and quenching technique followed by the electron probe X-ray microanalysis (EPMA). The liquidus of the "CuO 0.5 "-AlO 1.5 -SiO 2 system, including the two 2-liquid miscibility gaps in the system as well as the cuprite (Cu 2 O), corundum (Al 2 O 3), delafossite (CuAlO 2), tridymite and cristobalite (Si 1-x (CuAl) x O 2), and mullite (Al 6+2x Si 2-2x O 13-x) primary phase fields has been characterized. New experimental results together with phase equilibria and thermodynamic literature data were used to obtain a self-consistent set of parameters of the thermodynamic model for all phases. The liquidus projection of the "CuO 0.5 "-AlO 1.5 -SiO 2 system was presented for the first time in the full range of temperatures and compositions. It was found that the simultaneous dissolution of a small amount of alumina and copper oxide (CuAlO 2) in SiO 2 phases stabilize cristobalite over tridymite at low temperatures. [ABSTRACT FROM AUTHOR]

Knowledge of the liquidus is important for the design and processing of many materials. For instance, deep eutectics are important for the design of metallic glasses, and recently multi-principal element alloys have been designed based on eutectic compositions or melting temperatures extrapolated from binary liquidus data. In this study, we provide a general framework for predicting binary liquidus only from the properties of the pure elements and thermodynamic properties calculated by Miedema’s model. Our framework combines three machine learning models that are trained and evaluated on liquidus data collected from 466 CALPHAD assessments of binary phase diagrams. The first model predicts the formation of liquid miscibility gaps with a prediction accuracy of 95.3%, outperforming the empirical Mott model. The second and third models predict the equilibrium onset temperature of solidification and the critical temperature of liquid miscibility gaps, respectively. An important feature of our models is that they can give indications of the presence of congruent melting phases and eutectics. Using our framework, we predict the liquidus in 1563 binary systems not included in our CALPHAD dataset, many of which are unknown. By collecting more data, our framework will continue to grow towards better liquidus prediction.

A notable number of scientific works aided by thermal analysis methods are available in the literature concerning superalloys. The most frequently applied techniques are DSC, DTA, and TG. Although types of thermal effects investigated by various authors are limited, it is not difficult to find debatable interpretations of curves and characteristic temperatures, even in the case of recent papers. This circumstance was motivation for the work. In this study, basing on literature data and own experiences, we would like to discuss some methodological aspects of thermal analysis. This need results from multiplicity of ways that different authors determine the same characteristic temperatures. The research involves interpretation of heating and cooling curves (DTA, DSC) in view of determination of characteristic temperatures (solidus, liquidus), order–disorder transitions, and other thermal effects typical for Ni- and Co-based superalloys. We discuss different approaches in analysis of thermal effects, present in literature data, and draw the reader's attention to some potential problems related to data interpretation. The intention is to point some disputed methodological aspects and possibly systematize interpretation of effects present in thermal analysis of superalloys. [ABSTRACT FROM AUTHOR]

Phase equilibria of the CaO-SiO2-Sc2O3 system at 1400 and 1600 °C were examined by using quenching technology followed by sample characterization using electron probe microanalysis wavelength-dispersive spectroscopy, scanning electron microscopy and x-ray diffraction. The Sc2O3 solubility in the solid solution phase of Ca2SiO4 and the range of the liquid phase region was determined at experimental temperatures (T = 1400, 1500, 1600 °C). Phase diagrams were established according to the phase relations, further supporting the exploration of the feasibility of rare earth elements recovery from pyrometallurgical smelting slag. [ABSTRACT FROM AUTHOR]

[Display omitted] • A TPT description of the polarization effects in binary molten salts was proposed. • Expressions for charge-dipole contribution to the chemical potential were used. • Calculation of liquidus in binary eutectic alkali-halide mixtures was carried out. • Two variants of the model were considered, including the EoS and without it. • Errors for most mixtures of NaF–NaCl, CsF–CsCl, NaF–CsF, and NaCl–CsCl were 5–10 %. A statistical-thermodynamic model that makes it possible to describe with good accuracy phase equilibria between melt and crystal in binary alkali halide mixtures with common cations and anions is proposed. This model is based on the thermodynamic perturbation theory, which takes into account the charge-dipole contribution to the interionic interaction of binary molten salts using a multicomponent mixture of charged hard spheres as a reference system. Specific expressions for chemical potentials, taking into account the charge-induced dipole interaction in the molten phase, are presented within the developed approach. Considering binary eutectic mixtures NaF–NaCl, CsF–CsCl, NaF–CsF, and NaCl–CsCl as an example, the liquidus curves obtained in two series of calculations are shown: with the equation of state and without it. The discrepancies between the calculated and experimental data on the position of eutectic equilibrium for most of the considered mixtures do not exceed about 10 percent on the temperature scale and 5 percent on the composition when using only the tabulated values of ionic radii and polarizabilities without any adjustment. [ABSTRACT FROM AUTHOR]

The utilization of rare earth resources, especially secondary resources (e.g., RE-oxide system slag), has been limited by the lack of thermodynamic information. In order to supplement and improve the thermodynamic data related to rare earth, the equilibrium experiments of SiO 2 –Ce 2 O 3 –CaO-25 wt %Al 2 O 3 system phase diagram was carried out at 1673 K and 1773 K by the high-temperature isothermal equilibration/quenching technique in current paper. The composition of seven phase regions were determined by FE-SEM, XRD, EPMA and XRF analysis on the samples obtained by high temperature equilibrium technology at 1673 K and 1773 K, including the primary crystal regions of three compounds (C 2 AS, 2CaO·SiO 2 , CaO·2Ce 2 O 3 ·3SiO 2) and three three-phase coexistence regions (L + C 2 AS + 2CaO·SiO 2 , L + C 2 AS + CaO·2Ce 2 O 3 ·3SiO 2 , L + CaO·2Ce 2 O 3 ·3SiO 2 +CeAl 11 O 18) and a liquid region. The phase relations and isotherms of SiO 2 –Ce 2 O 3 –CaO-25 wt %Al 2 O 3 system obtained in current work are beneficial to the recycling of rare earth resources containing cerium. [ABSTRACT FROM AUTHOR]

Four-component systems comprising alkali-metal halides and chromates are used as fused electrolytes for chemical current sources, heat-storage materials, media for the synthesis of various compounds, etc. The Li,K||F,Cl,CrO4 reciprocal four-component system has been analyzed. The system has been triangulated to simplexes using theory of graphs. The phase tree of the system has been designed and used to predict the number of compositions of crystallizing phases in the stable elements. The phases crystallizing in the LiF–KCl–K2CrO4 stable triangle were identified by X-ray powder diffraction. Phase equilibria in the LiF–LiCl–Li2CrO4–KCl stable tetrahedron have been studied by differential thermal analysis. The characteristics of the four-component eutectic alloy were determined (equiv. %): LiF, 1.0; LiCl, 29.8; Li2CrO4, 45.5; KCl, 23.7; melting point, 305°С. [ABSTRACT FROM AUTHOR]

Cyclic thermal analysis is used to study the effect of overheating ΔT+ of a melt on the presolidification supercooling of gallium–indium alloys. The existence of deep supercooling with respect to the liquidus is found for hypoeutectic alloys, whereas, for hypereutectic alloys, the supercooling is found only with respect to solidus TE (eutectic transformation line). The activities and the coefficients of activity of constituents are calculated at the onset of quasi-equilibrium and nonequilibrium explosive solidification. When the composition approaches the eutectic one, the activity of both constituents is found to decrease. [ABSTRACT FROM AUTHOR]

An integrated experimental and thermodynamic modeling study of the phase equilibria in the 'CuO 0.5 '-MgO-SiO 2 system in equilibrium with liquid Cu metal has been undertaken to better understand the reactions between MgO-based refractories and liquid slag in copper converting and refining processes. New experimental phase equilibria data at 1250–1680 °C were obtained for this system using a high-temperature equilibration of synthetic mixtures with predetermined compositions in silica ampoules or magnesia crucibles, a rapid quenching technique, and electron probe X-ray microanalysis of the equilibrated phase compositions. The system has been shown to contain primary phase fields of cristobalite (SiO 2), tridymite (SiO 2), pyroxene/protoenstatite (MgSiO 3), olivine/forsterite (Mg 2 SiO 4), periclase (MgO), and cuprite (Cu 2 O). Three regions of 2-liquid immiscibility were found—two in the high-silica range of compositions above the cristobalite primary phase field (close to 'CuO 0.5 '-SiO 2 and MgO–SiO 2 binaries) and one in the low-SiO 2 , high-'CuO 0.5 ' compositional region above the periclase and olivine phase fields. The results obtained in this study indicate that silica in high-copper refining slags likely led to olivine and pyroxene phase formation, increased solubility of MgO in liquid slag, and decline in the performance of MgO-based refractories. New experimental data were used in the development of a thermodynamic database describing this pseudo-ternary system. [ABSTRACT FROM AUTHOR]

The paper presents experimental results on the solubility of fluorides in fluid-saturated melt of alkaline ultrapotassic syenite-porphyry from the Gross gold ore deposit in southern Yakutia at T = 600–800°C, P = 150–260 MPa. The experiments were carried out to confirm the assumption of high solubility of fluorine in ultrapotassic syenite melt, which could contribute to the formation of specific and low-viscosity melts that were emplaced in the form of a syenite porphyry sill. The solid products after the experiments contained aluminosilicate glass, potassium feldspar, fluorite, quartz, and two fluoride phases differing in composition (potassium and aluminum fluoride and potassium and magnesium fluoride). The experimental results led us to determine a high maximum solubility of fluorine in the melt: up to 4.2–4.6 wt %, with the maximum F content found in the lowest temperature melt at 625°C. The solidus and liquidus temperatures of the syenite melt were estimated at 600–625 and 650–800°C, respectively. The aqueous fluoride fluid coexisting in equilibrium with the melt was determined to be alkaline. Potassium feldspar was the first to crystallize from the melt in the experiments, which is consistent with what is observed in samples of the naturally occurring rocks. [ABSTRACT FROM AUTHOR]

A projection of the liquidus surface of the quasi-ternary system Cu2S-In2S3-FeS was constructed as a result of experimental studies of quasi-binary and non-quasi-binary sections and based on the data on binary systems comprising a ternary system. Each section (six quasi-binary and four non-quasi-binary ones) was studied separately using complex methods of physicochemical analysis: differential thermal analysis, X-ray phase analysis, and microstructural analysis. It was found that the quasi-ternary system Cu2S-In2S3-FeS has six fields of primary crystallisation of separate phases and eleven monovariant equilibrium curves along which two phases are co-crystallised. Non-variant equilibrium points were obtained through the extrapolation of the direction of monovariant equilibrium curves. The quasi-ternary system Cu2S-In2S3-FeS is characterised by 17 non-variant equilibrium points, where Е1-Е5 are triple eutectic points. The projection diagram of the liquidus surface is characterised by three crystallisation fields of the initial componets (Cu2S, In2S3, FeS), four fields of binary compounds, and one field of a complex compound (CuFeIn3S6). Since complete solubility of the initial components in liquid and solid states is observed in the quasi-binary section CuIn5S8‑FeIn2S4, the fields of primary crystallisation of CuIn5S8 and FeIn2S4 are absent; they are replaced by an unlimited solid solution based on these components. The fields of primary crystallisation of Cu2S, FeS, and CuInS2 are the most extensive in the ternary system Cu2S-In2S3-FeS. The reactions occurring at monovariant equilibrium points are presented.

A thermodynamic model is proposed for condensed phases in the ternary system Nb–Zr–N in the range 298–3000 K. The model is based on available experimental data and previously reported models of the constituent binaries Nb–Zr, Nb–N, and Zr–N. It is consistent with a previously reported subsolidus phase diagram of the Nb–Zr–N system and allows one to assess phase equilibria involving liquid phase. [ABSTRACT FROM AUTHOR]

Phase equilibria studies were undertaken on the "CuO 0.5 "-CaO-SiO 2 system in equilibrium with metallic copper to provide fundamental information on the reactions taking place between slags and refractory materials in metallurgical furnaces. The liquidus isotherms between 1160 and 1706 °C in the tridymite and cristobalite (SiO 2), cuprite (Cu 2 O), pseudowollastonite (CaSiO 3), rankinite (Ca 3 Si 2 O 7) and dicalcium silicate (Ca 2 SiO 4) primary phase fields, and the 2-liquid miscibility gaps in the silica-rich corner and low-silica area of the system, were experimentally determined using the equilibration and quenching technique, followed by the electron probe X-ray microanalysis (EPMA) of phase compositions. The liquidus surface of the "CuO 0.5 "-CaO-SiO 2 system has been constructed. The dissolution of copper oxide in the tridymite and cristobalite (SiO 2) was shown to be negligible. The data obtained are used for the optimization of the thermodynamic database for the copper-containing systems. [ABSTRACT FROM AUTHOR]

Chemical reactions between As2Te3 and Сr2Тe3 in the As2Te3–Сr2Тe3 system, which is a quasi-binary section of the As–Cr–Te ternary system, were studied by physicochemical methods (DTA, XRD, microstructure observations, microhardness measurements, and density determinations), and a relevant Т–х diagram was plotted. The As2Te3–Cr2Te3 system forms one chemical compound, namely, CrAsTe3, which melts incongruently at 375°C. Microstructural analysis showed that at room temperature, As2Te3-base solid solutions extend to 3.5 mol % Cr2Te3 and Cr2Te3-base solid solutions extend to 5 mol % As2Te3. The α phase (As2Te3-base solid solutions) and CrAsТe3 form a 15 mol % Cr2Тe3 eutectic at 335°С. X-ray diffraction showed that CrAsТe3 crystallizes in tetragonal crystal system with the unit cell parameters a = 14.246 Å, c = 5.993 Å, ρpycn = 6.57 g/cm3, ρx = 6.96 g/cm3. [ABSTRACT FROM AUTHOR]

Experimental measurements have been made of the compositions of slag, matte and tridymite phases in chemical equilibrium in the Cu-Fe-O-S-Si system at 1300°C, p(SO2) = 0.25 atm and selected oxygen partial pressures. The high temperature equilibration experiments were conducted using silica substrates under controlled CO-CO2-SO2-Ar gas atmospheres. The resulting phases obtained from the equilibrations were retained at room temperature through rapid quenching of the samples. The condensed phase compositions from the equilibrium experiments were measured by Electron Probe X-ray Microanalysis (EPMA). The data obtained in the present study, combined with those from previous studies, have enabled the liquidus slag temperature to be accurately described as a function of Fe/SiO2 ratio at p(SO2) = 0.25 atm for temperatures between 1200 and 1300oC and mattes containing from ∼44 to ∼ 78 wt pct Cu. [ABSTRACT FROM AUTHOR]

Sb distribution in the phases of SiO2 saturated Sb-Fe-O-SiO2-CaO system was determined for the first time through hightemperature experiment and quenching techniques, followed by Electron probe X-ray microanalysis (EPMA) in air (Ptot = 1 atm, PO2 = 0.21 atm). The phases were quantified in the temperature range of 900°C-1200°C and the effects of Fe/SiO2 (mass fraction) and CaO/SiO2 (mass fraction) on Sb2O3 content in the Sb-Fe-O-SiO2-CaO system were investigated at 1200°C. The results indicated that the Sb-containing phase primarily existed in the solid solution phase at 1200°C. With the increase of temperature from 1100°C to 1200°C, the Sb2O3 content in the solid solution phase increased drastically from 7.52 wt% to 17.36 wt%. Lowering the values of CaO/SiO2 and Fe/SiO2 in the smelting process effectively reduced Sb2O3 content in the slag. The verification of the experiment results suggested that the antimony content in slag was 0.57 wt%, the crude antimony yield rate was lower than 4%, and the crude antimony grade was beyond 94 wt%, which meant that the reduction of antimony content in the slag could be achieved.

Multicomponent systems of alkali metal halides and chromates are used as molten electrolytes for chemical current sources, heat storage materials, etc. In this work, the ternary system RbF–RbBr–Rb2CrO4 was studied. The ternary systems МF–MBr–M2CrO4 (М = Li, Na, K, Rb, Cs) were analyzed by comparing the types of the liquidi of the systems in the series formed by successive replacement of the alkali metal with increasing its number in the periodic system. The RbF–RbBr–Rb2CrO4 system was investigated by differential thermal analysis. Phase equilibria in the system were explored; crystallizing phases were determined; and the characteristics of the ternary eutectic and the ternary peritectic were found to be (equiv. %) 39.5 RbF, 52.0 RbBr, 8.5 Rb2CrO4, the melting point 522°C and 19.7 RbF, 55.0 RbBr, 25.3 Rb2CrO4, the melting point 554°C, respectively. [ABSTRACT FROM AUTHOR]

In recent years, it has been shown that high pressurized solidification has been impeding cooling rate measurement in semisolid forging of aluminum alloys. This has restricted the establishment of solidification behavior, especially at the semisolid interface. In this paper, the solid fraction effect on semisolid forging of A380 aluminum alloy was investigated. Computer-aided cooling curve analysis, microscopic evaluation, and Archimedes density measurement were used to analyze the results. It was found that during solidification, the application of pressure at 0.2% solid fraction not only increased the cooling rate but also reduced the solidus temperature. The application of pressure at the same solid fraction also reduces the SDAS to 15.54 µm. However, pressure application at 63% solid fraction recorded the lowest porosity volume percentage and highest density values of 0.133% and 2.723 g, respectively. Further increase in the cooling rate had a slight effect on the SDAS refinement. [ABSTRACT FROM AUTHOR]

Phase equilibria in Six – Ge1-x nanoparticles of various compositions within the two-phase region between the liquidus and solidus temperatures have been simulated by using methods of the equilibrium chemical thermodynamics. It has been shown that the equilibrium compositions of liquid and solid phases dramatically depend on the initial composition of a nanoparticle and the character of such dependences is different at different temperatures. Reducing the size of a nanoparticle is accompanied by narrowing the temperature interval of the two-phase region.

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A thermodynamic model is proposed for condensed phases in the ternary system U–Zr–N in the range 298–2800 K. The model is based on previously reported models of the constituent binaries U–Zr, U–N, and Zr–N and available data on the properties of the pseudobinary system UN–ZrN. It allows one to calculate phase equilibria involving liquid phase. The model is used to calculate a number of isobaric–isothermal sections in the U–Zr–N system. [ABSTRACT FROM AUTHOR]

A thermodynamic perturbation theory model is developed to take into account the additional charge–dipole contribution to the free energy of molten alkali halide systems, and it is used to describe the melt–crystal equilibria in binary salt mixtures with common anions. The liquidus lines in the binary phase diagrams LiF–NaF, LiF–KF, NaF–KF, NaF–CsF, and KF–CsF of the eutectic type are calculated. The error in describing the liquidus lines in the phase diagrams of the fluoride mixtures with the use of the tabulated ionic radii and polarizabilities is at most 15% as compared to the available FactSage data. The discrepancies between the calculated and published data become more noticeable for systems containing larger and more polarizable cations. The position of the eutectic equilibrium point is found to shift toward a low-melting-point component by 5–10%, and the eutectic point temperature is lightly overestimated in comparison with the experimental results and the FactSage data. [ABSTRACT FROM AUTHOR]

The influence of the melt overheating temperature over the equilibrium liquidus and the cooling rate of it during crystallization, the effect of the temperature of the isothermal processing of the melt in the pre-crystallization period and in the temperature interval of crystallization under conditions of normal and high-speed thermal selection on the formation processes of cast structure was researched by methods of physical modeling using transparent model material (camphene). It has been established that the formation of a coarse-grained structure with significant overheating of the melt can be eliminated by its rapid cooling during crystallization, which ensures the formation of a fine-grained structure with a high dispersion of the dendritic structure. It is shown that in a narrow temperature range of underliquidus area during the isothermal processing solid phase crystals form and accumulate without substantially increasing their size, providing the formation of a dispersed cast structure with subsequent rapid melt cooling.

A new functional cast iron alloyed with transition metals was synthesized for the manufacture of the working part of rolls. Its properties were studied using complex methods of physicochemical analysis (DTA, X-ray, MSA and measurement of hardness and microhardness). It was found that traces of martenicite, cementite, carbon (graphite) and α-ferritin are released in the subsolidus during cooling of molten iron in the studied concentration range (2.7 ÷ 3.5 %wt C. It includes transition metals as an alloying agent increasing resistance of cast iron to twisting, corrosion and destruction during operation. [ABSTRACT FROM AUTHOR]

Sb distribution in the phases of SiO2 saturated Sb-Fe-O-SiO2-CaO system was determined for the first time through heightemperature experiment and quenching techniques, followed by Electron probe X-ray microanalysis (EPMA) in air (Ptot = 1 atm, PO2 = 0.21 atm). The phases were quantified in the temperature range of 900 °C-1200 °C and the effects of Fe/SiO2 (mass fraction) and CaO/SiO2 (mass fraction) on Sb2O3 content in the Sb-Fe-O-SiO2-CaO system were investigated at 1200 °C. The results indicated that the Sb-containing phase primarily existed in the solid solution phase at 1200 °C. With the increase of temperature from 1100 °C to 1200 °C, the Sb2O3 content in the solid solution phase increased drastically from 7.52 wt% to 17.36 wt%. Lowering the values of CaO/SiO2 and Fe/SiO2 in the smelting process effectively reduced Sb2O3 content in the slag. The verification of the experiment results suggested that the antimony content in slag was 0.57 wt%, the crude antimony yield rate was lower than 4%, and the crude antimony grade was beyond 94 wt%, which meant that the reduction of antimony content in the slag could be achieved. [ABSTRACT FROM AUTHOR]

Carbon equivalent of cast iron is known as the following equation: CE = [%C] + (1/3) [%Si]. This equation is basically calculated from the carbon solubility in hypereutectic composition. On the other hand, liquidus from hypoeutectic to eutectic composition in Fe–C phase diagram is well known. Liquidus temperature (hereinafter referred to as TL) can be measured easily with thermal analysis by focusing primary crystallization temperature. In this study, the effects of elements on TL and carbon equivalent in cast iron were examined from the view point of cooling curve, carbon flotation, and internal shrinkage, and a more accurate equation for calculating carbon equivalent is suggested. It is revealed by the experiment that the relationship between TL and elements from hypoeutectic to eutectic composition is as follows; TL (°C) = 1625 − 110 [%C] − 25 [%Si] + 3 [%Mn] − 35 [%P] − 71 [%S] − 2 [%Ni] − 7 [%Cr]. Dividing this equation by carbon coefficient, the carbon equivalent equation of liquidus (hereinafter referred to as CEL) from hypoeutectic to eutectic composition is obtained as follows: CEL = [%C] + 0.23 [%Si] − 0.03 [%Mn] + 0.32 [%P] + 0.64 [%S] + 0.02 [%Ni] + 0.06 [%Cr]. This CEL is different from the commonly used CE since it is determined from liquidus. We investigated how the difference of carbon equivalent (CE/CEL) application in the range of hypoeutectic to eutectic composition affected on the cast iron and revealed that CEL = [%C] + 0.23 [%Si] should be applicable. [ABSTRACT FROM AUTHOR]

The phase equilibria in the FeS-FeGa2S4-FeGaInS4 system were studied using the differential thermal and X-ray diffraction phase analysis. The projection of the liquidus surface and the isothermal sections of the phase diagram at 1200 and 900 K were constructed. It revealed that it belongs to quasiternary systems with monovariant eutectic and peritectoid equilibria. At 1200 K, the system was characterized by the presence of a continuous series of solid solutions along the boundary system FeGa2S4- FeGaInS4 (β-phase) as well as solid solutions based on the high-temperature modification FeS (α-phase) which formed a wide two-phase region α + β. The FeS-FeGa2S4 boundary system was characterized by the formation of the Fe2Ga2S5 ternary compound at 900 K. This compound formed Fe2Ga2S5+β and Fe2Ga2S5+ α+β heterogeneous regions below this temperature which significantly narrowed the two-phase region α + β. [ABSTRACT FROM AUTHOR]

By differential thermal analysis, the ternary systems MCl–MI–M2CrO4 (M = Rb, Cs) were studied, and the characteristics (melting points, concentrations of components) of alloys at invariant equilibrium points of the systems were determined. The studied systems are systems of the same type that form by varying the alkali metal cation with increasing atomic number of the cation. In all the binary systems constituting the ternary systems, eutectics form. Based on analyzing the faceting elements, it was assumed that eutectics form in the ternary systems. Low-melting eutectic mixtures of alkali-metal halides and chromates are chemically stable even in the molten state and have low viscosity and low volatility, which makes them suitable for using as heat-storage materials or electrolytes for chemical current sources. Consideration of the systems MCl–MI–M2CrO4 (M = Li, Na, K, Rb, Cs) showed that the varying alkali metal cation in them does not affect the morphology of the liquidus. [ABSTRACT FROM AUTHOR]