Ternary Sections Research Articles

AIPHAD, an active learning web application for visual understanding of phase diagrams

Phase diagrams provide considerable information that is vital for materials exploration. However, the determination of multidimensional phase diagrams typically requires a significant investment of time, cost, and human resources owing to the necessity of numerous experiments or simulations. Machine learning and artificial intelligence techniques present a viable solution for expediting phase diagrams investigations. Additionally, effective visualization is critical for understanding phase diagrams. This study reports the development of AIPHAD (Artificial Intelligence technique for PHAse Diagram), an open-source web application to assist in the investigation and visual understanding of phase diagrams using active learning. AIPHAD employs PDC (Phase Diagram Construction) algorithm, which operates on the principle of uncertainty sampling in active learning. The AIPHAD application facilitates the examination of five diagram types: two-variable diagrams, three-variable diagrams, ternary sections, ternary phase diagrams, and quaternary sections. The efficacy of the application is demonstrated in the study of the Fe-Ti-Sn ternary system, where it efficiently identified the presence of the Heusler phase. The integration of machine learning tools with traditional materials science approaches showcased in this study has the potential to drive groundbreaking advancements in materials exploration and discovery.

Calorimetric study of the enthalpy of mixing in the liquid systems Li-Zn and Li-Sn-Zn

Partial and integral molar enthalpies of mixing of binary liquid Li-Zn alloys and ternary liquid Li-Sn-Zn alloys were determined by drop calorimetry at 823 K. The binary system was investigated up to xZn = 0.85 and the integral mixing enthalpy was described with a Redlich-Kister-polynomial. Li-Zn shows an exothermic behavior and a minimum molar mixing enthalpy of about ΔHmix = -11.7 kJ⋅mol−1 at xZn = 0.6. The mixing enthalpy along nine ternary sections of Li-Sn-Zn (A: xLi/xSn ≈ 9:11, B: xLi/xSn ≈ 1:4, C: xSn/xZn ≈ 9:1, D: xSn/xZn ≈ 7:3, E: xSn/xZn ≈ 1:1, F: xLi/xZn ≈ 1:3, G: xLi/xZn ≈ 1:1, H: xLi/xZn ≈ 3:2, I: xLi/xZn ≈ 7:3) was investigated. Solid pieces of Li, Sn, and Zn respectively were dropped to the liquid binary starting alloys in the calorimeter at 823 K. The integral values at the crossing points of the various sections show excellent agreement. The course of the partial and integral enthalpy values along the sections A, D, E, F, G, H, and I indicate multiple-phase regions. The occurrence of such partially liquid and de-mixed liquid regions is discussed and compared with a calculated version of the isothermal section at 823 K which exhibits a large ternary liquid miscibility gap. The experimental ternary data allocated to the fully liquid monophasic regions was numerically fitted based on a Redlich-Kister-Muggianu polynomial for substitutional solutions including ternary interactions. In addition, a comparison with enthalpy values from the extrapolation methods based on binary data according to the Muggianu and Toop model, respectively, is shown. Both models fail to accurately reproduce the experimental values. Iso-enthalpy plots of calculated integral mixing enthalpy for stable and metastable fully homogeneous liquid alloys for the entire ternary system are shown.

Phase relations, structure, properties and DFT study of compounds in the Sc-rich part of the systems Sc-{Mn,Fe,Co,Ni}-Ga

Phase relations, structure, properties and DFT study of compounds in the Sc-rich part of the systems Sc-{Mn,Fe,Co,Ni}-Ga

Calculation of eutectics temperatures and compositions of multicomponent sections of the system (Mg, Ca, Sr, Ba)O—Al2O3—Cr2O3

With change in the structure of metallurgical production in Ukraine, the range of used refractory materials is expanding: the share of unshaped highquality refractories is growing, since this eliminates the time-consuming and energy-consuming operation of firing piece products, and also simplifies the operation of creating a lining layer. To establish the maximum possible operating temperature of materials developed on the basis of compositions of the optimal regions of multicomponent oxide system (Mg, Ca, Sr, Ba)O— Al2O3—Cr2O3, it was necessary to calculate the temperatures and compositions of the eutectics of binary, ternary and four-component sections, which was the purpose of this study.
 For calculations in binary sections, the Epstein — Howland method is most acceptable, and in three- and four-component sections — the solution of nonlinear equations system. It was found that to obtain a refractory unshaped material based on calcium aluminium chromite cement with periclase as a filler, it is necessary to adjust the phase composition of the cement towards an increased CaCr2O4 content, and the total composition must contains at least 75 wt. % periclase or magnesium spinel. In addition, in the case of alumina hydrates formation as a result of cement hydration processes, magnesium spinel will be synthesized as part of a refractory unshaped material during service. To obtain refractory unshaped materials based on strontium aluminium chromite cement and periclase as filler, it is necessary to increase the SrAl2O4 content and minimize the Sr3Al2O6 content in the cement composition, while the filler content in the composition can vary within wide limits, since the melting temperature of such compositions will be more than 1700 °C. To create refractory unshaped materials based on barium aluminium chromite cements, it is necessary to increase the content of BaAl2O4 in the cement composition as the most hydraulically active and refractory component and the composition of the composite material should be low- or ultra-low-cement in order to increase the operating temperature. In addition, in the case of chromium hydroxides formation during the hydration of aluminium chromite cement, chromium spinel will be synthesized in the composition during service, increasing the refractoriness of resulting composition. Thus, by varying the type and phase composition of cement and the ratio of cement and aggregates in the concrete composition, it is possible to obtain unshaped materials with a wide operating temperature range for use in heat-stressed areas of high-temperature aggregates.

Study of some numerical characteristic parameters of Sb2S3-As2S3-Sb2Te3 vitreous compositions calculated from their chemical formula obtained by EDS experiments

Glasses of binary systems (Sb2S3-As2S3 and Sb2Te3-As2S3) and ternary sections (containing 10, 20 and 40 mol% of Sb2Te3) belonging to Sb2S3-As2S3-Sb2Te3 system were prepared by rapid quenching method in ice water of their liquid phases. From chemical formulas obtained by using Energy Dispersion Spectroscopy (EDS), average values of Sb2S3-As2S3-Sb2Te3 glasses’ parameters such as coordination number (Z), atomic radius (Rav), atomic number (Zav), atomic molar mass (Mav) and electronegativity (av) were calculated. These parameters were used to explain the formation of the glasses in the Sb2S3-As2S3-Sb2Te3 system by following their evolution as a function of the As2S3 content.

Low temperature study of phase equilibria in the Co–Ni–W ternary system: Evidence of a new intermetallic phase Co3W-D0a

Tungsten heavy alloys (Co–Ni–W) of different compositions were prepared by powder metallurgy (solid sintering), heat treated at 800 °C and 1000 °C and subsequently analyzed. The experimental phase identifications and composition measurements emphasized discrepancies compared to the isothermal ternary sections simulated with commercial thermodynamic databases. The isothermal sections at 800 °C and 1000 °C were found more complex than expected since a new intermetallic phase appeared to be stable (D0a structure - Cu3Ti prototype). Likewise, an interpretation of phase equilibria evolution with temperature was established to reach agreement with high temperature data. Formation enthalpies associated with the new phase were obtained through first-principles calculations and supported experimental results as they confirmed the stabilizing role of Ni addition for the D0a structure.

Experimental Study of High Temperature Phase Equilibria in the Iron-Rich Part of the Fe-P and Fe-C-P Systems

During the solidification of steel, phosphorus strongly segregates in the interdendritic liquid phase. In the continuous casting process, even low levels of P may have a detrimental effect on the final product quality. However, phosphorus is partly added up to 0.10 wt pct to improve the mechanical properties of advanced steel grades nowadays, e.g., High-Strength Interstitial-Free (HSIF). To provide new experimental data for the development of thermodynamic databases and solidification models for P alloyed steel grades, phase equilibria in the Fe-P and Fe-C-P key systems were studied up to 1550 °C using differential scanning calorimetry (DSC) and high temperature laser scanning confocal microscopy (HT-LSCM). Special focus was placed on solid/liquid equilibrium temperatures in the Fe-rich part of the binary Fe-P system between 0.025 and 9 wt pct P. In the ternary system, three isoplethal sections with 0.10 mass pct. P, 0.20 mass pct. C and constant mass percent ratio P/C of 2 were investigated. In the latter section, HT-LSCM observations were linked with DSC signals to optically identify present phase stabilities. Particularly at [pct P] < 1, significant differences between performed measurements and calculated phase equilibrium temperatures using thermodynamic assessments from the literature were identified. In all ternary sections, the experiments indicate less influence of P on the hypo-peritectic range compared to the thermodynamic calculations.

Further Insight into Interfacial Interactions in Iron/Liquid Zn-Al System

In the galvannealing process, steel strips are immersed in molten zinc containing 0.100 to 0.135 wt pct Al at 450 °C. The coating obtained is composed of a thin intermetallic compounds’ layer called the inhibition layer (200 nm) covered with a thick zinc layer (10 µm). The nature of this inhibition layer has been investigated here for a galvanizing bath with a low Al content. The inhibition layer formed on industrial low-alloyed steels was characterized by transmission electron microscopy and atom probe tomography. The inhibition layer is composed of a thin Fe2Al5Znx layer (20 nm), covered with a thicker δ layer (200 nm). The Fe2Al5Znx layer is discontinuous at the lowest bath Al content. Small precipitates (20 nm in diameter) with a stoichiometry corresponding to Fe3Al-containing Zn were also found for the first time in the δ phase. The microstructure of the inhibition layer can be described with diffusion paths drawn in the Al-Fe-Zn ternary section at 450 °C. This means that all interfaces of the inhibition layer are at thermodynamic equilibrium. The Fe2Al5Znx layer is formed on the steel surface before the δ layer. The nucleation and growth of the Fe3Al-Zn particles probably occur in the liquid metal at the same time as δ.

Calculation and analysis of temperatures and compositions eutectics binary and ternary sections of systems CаО—CoO—Al2О3 and ВаО—СоО—Al2О3

This study focuses on the calculation and analysis of temperatures and compositions of eutectics binary and ternary sections of CaO—CoO—Al2O3 and BaO—СoO—Al2O3 systems with the aim of possibility establishing of developing compositions of calcium­aluminate and barium­aluminate refractory cements with the use of spent aluminum­cobalt­molybdenum catalyst without additional processing. The temperatures and compositions of eutectic binary and ternary sections of the CaO—CoO—Al2O3 and BaO—CoO—Al2O3 systems were calculated. The temperatures and compositions of eutectics in binary sections of the systems were calculated using the Epstein—Howland formulas, and for three­component sections, by solving a system of nonlinear equations. The calculation results and characteristics of binary and ternary eutectic sections of the three­component systems CaO—CoO—Al2O3 and BaO—СoO—Al2O3 were presented. The graphic images of liquidus and solidus surfaces of the optimal regions were given. It was found that, composite materials based on these systems can be used to obtain binding materials with an operating temperature above 1250 C. The most suitable areas to get heat­resistant special purpose binders with increased operational temperature have been determined.

Tb–Al–Si systems

There are presently limited information regarding the liquid–solid equilibria at the (Al)-rich region of the different R–Al–Si systems (R = rare earth elements). These data, along with the ternary systems isothermal section, are needed to outline the design, plan and develop new Al–Si-based alloys. The effect of the lanthanide terbium addition to the Al–Si system, in the Al-rich corner, has been experimentally studied. The constitution of the alloys and the liquidus surface projection have been determined by means of differential thermal analysis, scanning electron microscopy, electron microprobe analysis and X-ray powder diffraction. In the system investigated have been identified five regions of primary crystallization: TbAl(3 − x)Six, Tb2Al3Si2, TbAlxSi2 − x, (Al) and (Si).

Experimental Study of the Phase Equilibria in the R-Al-Si Ternary Systems (R: Rare Earth Element) the Ho-Al-Si Isothermal Section at 500?C

The effect of holmium addition to the Al-Si system has been experimentally studied, as the isothermal section at 500?C. The constitution of the alloys has been determined by means of scanning electron microscopy (SEM), electron microprobe analysis (EDXS) and X-ray powder diffraction. The knowledge of the phase relationships in the R-Al-Si ternary systems (R: rare earths element) is essential to deeply understand the technological properties of the Al-Si based alloys, that are useful in different industrial fields. In the system investigated have been identify nineteen ternary fields and twelve two phase fields. Three ternary compounds have been found in this ternary section: τ2-Ho2Al3Si2 (mS14-Y2Al3Si2), τ4-Ho2AlSi2 (oI10-W2CoB2) and τ5-Ho6Al3Si (tI80-Tb6Al3Si). The results obtained can be useful compared with the other known R-Al-Si systems also for predictive purposes.

Phase diagrams and elastic properties of the Fe-Cr-Al alloys: A first-principles based study

The phase diagrams and elastic properties of the Fe-Cr-Al alloys in full-temperature and all-compositional ranges are calculated. By combining first-principles calculations and cluster variation method, binary and ternary phase diagrams are obtained. A new ternary ordered phase B32 which is different from ternary extension of binary phases appears in the ternary section around temperature of 600 K. The binary FeAl phases show an extremely high solubility for Cr, while the binary CrAl phase solid solution has a low solubility for Fe. By combining first-principles calculations and cluster expansion method, the bulk modulus, shear modulus and Poisson's ratio are calculated. The shear modulus and Poisson's ratio show a strong ordering dependency, while the ordering dependency in bulk modulus is weak. Disordered Fe-Cr alloys with a little Al solvent shows ductile property, the Al-rich corner has brittle property.

Investigation of the phase equilibria at 773 K and metallic glass regions in the Ag-Al-Zr ternary system

Forty-eight different Ag–Al–Zr ternary alloys were prepared in various compositions to determine the metallic glass region in the Ag–Al–Zr ternary system. Experimental results indicated that the metallic glass region in the Ag–Al–Zr ternary system is Ag20–30Al10–30Zr50–60. The Ag20Al30Zr50 and Ag30Al20Zr50 alloys are supposed to have the best glass-forming ability in the Ag–Al–Zr ternary system. The phase equilibria of the Ag–Al–Zr ternary system at 773 K (500 °C) were investigated and compared with the metallic glass region results in the Ag–Al–Zr ternary system. Ternary isothermal sections of the Ag–Al–Zr system at 773 K (500 °C) were established and two ternary intermetallic phases were observed in this isothermal section.

In the quest of single phase multi-component multiprincipal high entropy alloys

The design and development of single phase multi-component high entropy alloy (HEA) using conventional hit and trial method is a challenging job due to the large number of experimental trials required to find the right alloy composition from possible combinations of various alloying elements in the multi-component system. Present investigation reports a novel CALculation of PHAse Diagram (CALPHAD) based approach, which can significantly reduce number of experimental trials in a very time effective manner to find single phase HEAs. Here, 1287 equiatomic five-component alloy systems were studied using both parametric and CALPHAD approaches to find single phase fcc and bcc HEAs. The parametric approach reduced the number of trials to 124 whereas; CALPHAD approach reduced the number of alloy compositions to 10. Further, the experimental investigation on the 10 alloy systems reveals that six of them form single phase HEAs. In addition, Thermo-Calc software was also used effectively to draw the isothermal pseudo ternary sections at 1000 K varying all constituents elements from 5 to 35 atomic percent for the CoCuFeMnNi alloy system. Experimental evidences confirmed that the isothermal pseudo ternary diagrams are very useful to design non equiatomic single phase as well as multiphase HEAs in the absence of phase diagram for the five component systems.

Experimental determination of the liquid phase domain of the Cu–O–ZnO–SiO2 system in equilibrium with air

ABSTRACTPhase relationships and liquidus in the Cu–O–ZnO–SiO2 system in air (ptot = 1 atm, ) were experimentally determined using the equilibration/quenching/EPMA technique at temperatures 1473, 1573 and 1673 K. No ternary compounds were found. Three solid primary phases [tridymite (SiO2), willemite (Zn2SiO4) and wurtzite (ZnO)] and two three-phase equilibria (liquid oxide + tridymite + willemite, and liquid oxide + willemite + wurtzite) were characterised. Results from the present study and previous studies have been used to construct schematically the liquidus isothermals of the Cu2O–ZnO–SiO2 system in equilibrium with air. The liquidus surface expands along with increasing temperature, and moves towards the primary-phase fields of willemite and wurtzite simultaneously. The constructed liquidus isopleths have been compared with the isothermal ternary sections calculated by MTDATA 5.10 software and its Mtox 8.1 database. The differences are significant, and thus the system requires a re-assessment.

Phase Equilibrium of Mg-Nd-Zn System near Mg-Nd Side at 400°C

The equilibrium alloys closed to Mg-Nd side in the Mg-rich corner of the Mg-Zn-Nd system at 400°C have been investigated by scanning electron microscopy, electron probe microanalysis and X-ray diffraction. The binary solid solutions Mg12Nd and Mg3Nd with the solubility of Zn have been identified. The maximum solubility of Zn in Mg12Nd is 4.8at%, and Mg12Nd phase can be in equilibrium with Mg solid solution. However, only when the solubility range of Zn in 26at%~32.2at%, Mg3Nd can be in two-phase equilibrium with Mg solid solution. As the results, two two-phase regions as Mg+Mg12Nd and Mg+Mg3Nd and a three-phase region as Mg+Mg12Nd+Mg3Nd in Mg-Nd-Zn ternary isothermal section at 400°C have been identified.

Measurement of Activity of Indium in Liquid Bi-In-Sn Alloys by EMF Method

The electrochemical technique based on a molten salt electrolyte galvanic cell has been used to measure the activity of indium in liquid Bi-In-Sn alloys in the temperature range of 723 K to 855 K along three ternary sections. The activity of tin in Bi-Sn binary alloys has also been measured by the same technique in the above temperature range. The activity of indium in Bi-In-Sn alloys shows negative deviation from Raoult’s law for most of the compositions and slight positive deviations for a few indium-rich compositions. The ternary excess molar free energies have been calculated by Darken’s treatment. Isoactivity curves at 813 K in the ternary Bi-In-Sn alloys were derived by combining the activity data of In-Sn and Bi-In alloys. The values of excess molar free energy obtained in this study are compared with those calculated from the Muggianu model at 813 K.

Experimental phase equilibria of the system Cu–O–CaO–Al2O3 in air

Phase equilibria of the system Cu–O–CaO–Al2O3 at Po2 of 21278.25Pa was experimentally investigated for the first time using equilibration techniques. Composition of glassy molten phase and all solids in equilibrium were quantified using Electron Probe Micro-Analyzer (EPMA). Isothermal ternary sections of the ‘Cu2O’–CaO–Al2O3 system in the temperature range 1150–1400°C in steps of 50°C have been constructed based on three phase equilibria experimental data. From the triple points data obtained, large deviations exist among previously thermodynamically assessed diagrams and experimental results of this study. Especially triple points one (1), with halite and tricalcium aluminate as solid phases, and triple point four (4), with monocalcium aluminate and monocalcium dialuminate as solid phases, between 1350 and 1400°C, where the deviations in Al2O3, ‘Cu2O’ and CaO contents of the liquid phase reach 40wt%. Thus there is a need for re-assessment with the new experimental data.

Partial and integral enthalpies of mixing in the liquid Ag–In–Sn–Zn quaternary alloys

The partial and integral enthalpies of mixing of liquid quaternary Ag–In–Sn–Zn alloys have been measured at 500 °C along seven ternary sections: In0.450Sn0.450Zn0.100, In0.375Sn0.375Zn0.250, In0.333Sn0.333Zn0.334, In0.225Sn0.550Zn0.225, In0.100Sn0.800Zn0.100, In0.550Sn0.225Zn0.225 and In0.800Sn0.100Zn0.100. The measurements were carried out using a Calvet-type microcalorimeter and drop calorimetric technique. Additionally, the enthalpies of mixing of the liquid Ag–In–Sn–Zn have been calculated using the traditional Kohler, Muggianu, Toop and Hillert geometric models and compared to the experimental one.

Pb-free solders: Experimental and calculated enthalpy of mixing of the liquid Au–In–Sn–Zn quaternary system

The partial and the integral enthalpies of mixing of liquid Au–In–Sn–Zn quaternary alloys have been measured at 500°C along five ternary sections: In0.800Sn0.100Zn0.100, In0.550Sn0.225Zn0.225, In0.100Sn0.800Zn0.100, In0.450Sn0.450Zn0.100, and In0.225Sn0.550Zn0.225. In addition, using Kohler, Muggianu and Toop geometric models, the enthalpies of mixing were calculated and compared to the experimental one.