Pub Date : 2025-07-12DOI: 10.1016/j.calphad.2025.102858
Zhaohui Long , Shan Yang , Lunjun Gong , Hong Bo , Cong Li , Haohan She , Fucheng Yin
The phase equilibria in the Si-Zr-Ag ternary system at 650 °C and 750 °C were investigated using the equilibrated alloy approach. Scanning electron microscopy equipped with energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD) have been applied to characterize the phase constitution of the alloys. At 650 °C and 750 °C, Six three-phase regions have been detected. The ternary compounds τ1 and τ2 were found in the two isothermal sections. τ1 was identified as a body-centered cubic structure by transmission electron microscopy (TEM) analysis, with the lattice parameters determined as a = 0.3738 nm, α = β = γ = 90°. Based on the experimental results on phase equilibrium, the CALPHAD approach was used to develop the thermodynamic description of the Si-Zr-Ag ternary system. The calculated isothermal sections show excellent agreement with the experimental ones. Then, the liquidus projection was predicted with the obtained thermodynamic parameters.
{"title":"Experimental investigation and thermodynamic calculation of the Si-Zr-Ag ternary system","authors":"Zhaohui Long , Shan Yang , Lunjun Gong , Hong Bo , Cong Li , Haohan She , Fucheng Yin","doi":"10.1016/j.calphad.2025.102858","DOIUrl":"10.1016/j.calphad.2025.102858","url":null,"abstract":"<div><div>The phase equilibria in the Si-Zr-Ag ternary system at 650 °C and 750 °C were investigated using the equilibrated alloy approach. Scanning electron microscopy equipped with energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD) have been applied to characterize the phase constitution of the alloys. At 650 °C and 750 °C, Six three-phase regions have been detected. The ternary compounds τ<sub>1</sub> and τ<sub>2</sub> were found in the two isothermal sections. τ<sub>1</sub> was identified as a body-centered cubic structure by transmission electron microscopy (TEM) analysis, with the lattice parameters determined as a = 0.3738 nm, α = β = γ = 90°. Based on the experimental results on phase equilibrium, the CALPHAD approach was used to develop the thermodynamic description of the Si-Zr-Ag ternary system. The calculated isothermal sections show excellent agreement with the experimental ones. Then, the liquidus projection was predicted with the obtained thermodynamic parameters.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102858"},"PeriodicalIF":1.9,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144611619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-10DOI: 10.1016/j.calphad.2025.102838
C. Frueh, C. Aras, Ö. Büyükuslu, M. to Baben
aiMP and aiOQ are databases derived from the 0 K density functional theory (DFT) calculations data stored in the Materials Project and Open Quantum Materials Database (OQMD) repositories, respectively. aiMP and aiOQ databases rely on methods to process 0 K DFT data using machine learning models trained on thousands of compounds. These models adjust formation enthalpies to improve consistency with existing CALPHAD (CALculation of PHAse Diagrams) databases and predict thermodynamic properties such as entropy and heat capacity as functions of temperature.
This work demonstrates three Materials Informatics applications of large-scale CALPHAD-compatible databases enabled by automated workflows.
First, a comparison was made between the SGTE Pure Substance database (SGPS), containing 3927 compounds, and the aiMP database, which includes overlapping entries for 1519 compounds. For these overlapping compounds, the enthalpy of formation, entropy at 298 K, and heat capacity at 298 K were analyzed. Any discrepancies exceeding the inherent error of the machine learning models were flagged. A literature survey was then conducted for compounds with larger discrepancies and erroneous data was confirmed in approximately 0.7% of the SGPS data.
Second, the aiMP database was used to estimate phase diagrams and identify potential new coating materials for SiC/SiC composites, which are under investigation as accident-tolerant fuel cladding materials.
Finally, it is shown that aiMP can serve as a starting point for both traditional and automated CALPHAD modeling. Three examples were explored Al-Ca, Mg-Si, and Ca-Li. These examples highlight the versatility of machine learning-enhanced thermodynamic databases in accelerating material discovery and improving database reliability.
aiMP和aiOQ数据库分别来源于存储在材料项目和开放量子材料数据库（OQMD）存储库中的0 K密度泛函理论（DFT）计算数据。aiMP和aiOQ数据库依赖于使用数千种化合物训练的机器学习模型来处理0 K DFT数据的方法。这些模型调整地层焓，以提高与现有CALPHAD（相图计算）数据库的一致性，并预测热力学性质，如熵和热容作为温度的函数。这项工作演示了三种材料信息学应用程序的大规模calphad兼容数据库启用自动化工作流程。首先，我们比较了包含3927种化合物的SGTE纯物质数据库（SGPS）和包含1519种化合物重叠条目的aiMP数据库。对这些重叠化合物的生成焓、298k时的熵和298k时的热容进行了分析。任何超出机器学习模型固有误差的差异都会被标记出来。然后对差异较大的化合物进行文献调查，在大约0.7%的SGPS数据中确认了错误数据。其次，aiMP数据库用于估计相图并确定潜在的SiC/SiC复合材料的新涂层材料，这些材料正在研究作为耐事故燃料包层材料。最后，表明aiMP可以作为传统和自动化CALPHAD建模的起点。以Al-Ca、Mg-Si和Ca-Li为例。这些例子突出了机器学习增强的热力学数据库在加速材料发现和提高数据库可靠性方面的多功能性。
{"title":"aiMP and aiOQ databases in FactSage: Materials informatics relying on ab initio, machine learning and CALPHAD data","authors":"C. Frueh, C. Aras, Ö. Büyükuslu, M. to Baben","doi":"10.1016/j.calphad.2025.102838","DOIUrl":"10.1016/j.calphad.2025.102838","url":null,"abstract":"<div><div>aiMP and aiOQ are databases derived from the 0 K density functional theory (DFT) calculations data stored in the Materials Project and Open Quantum Materials Database (OQMD) repositories, respectively. aiMP and aiOQ databases rely on methods to process 0 K DFT data using machine learning models trained on thousands of compounds. These models adjust formation enthalpies to improve consistency with existing CALPHAD (CALculation of PHAse Diagrams) databases and predict thermodynamic properties such as entropy and heat capacity as functions of temperature.</div><div>This work demonstrates three Materials Informatics applications of large-scale CALPHAD-compatible databases enabled by automated workflows.</div><div>First, a comparison was made between the SGTE Pure Substance database (SGPS), containing 3927 compounds, and the aiMP database, which includes overlapping entries for 1519 compounds. For these overlapping compounds, the enthalpy of formation, entropy at 298 K, and heat capacity at 298 K were analyzed. Any discrepancies exceeding the inherent error of the machine learning models were flagged. A literature survey was then conducted for compounds with larger discrepancies and erroneous data was confirmed in approximately 0.7% of the SGPS data.</div><div>Second, the aiMP database was used to estimate phase diagrams and identify potential new coating materials for SiC/SiC composites, which are under investigation as accident-tolerant fuel cladding materials.</div><div>Finally, it is shown that aiMP can serve as a starting point for both traditional and automated CALPHAD modeling. Three examples were explored Al-Ca, Mg-Si, and Ca-Li. These examples highlight the versatility of machine learning-enhanced thermodynamic databases in accelerating material discovery and improving database reliability.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102838"},"PeriodicalIF":1.9,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144588725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-09DOI: 10.1016/j.calphad.2025.102851
Weisheng Cao , Fan Zhang , Kamalnath Kadirvel , Shuanglin Chen , Eric Payton , Matthew Krug
This paper introduces PanEvolution, a modeling platform that integrates CALPHAD, microstructure modeling, and finite element method (FEM). This work represents the third generation of Pandat software, designed to simulate the microstructure evolution of metallic materials during conventional manufacturing processes. The key features of PanEvolution include: (1) direct coupling of CALPHAD with various FEM software packages. This enables FEM packages to obtain accurate input of phase information for multi-component alloys and perform simulations of microstructure evolution for technically important metallic alloys, including precipitation, recrystallization, grain growth, and coarsening, during conventional manufacturing processes such as forging and rolling. (2) an open architecture that facilitates the easy replacement and swapping of fast-acting microstructure models. This enables microstructure evolution and property models developed by academia or industry to be easily integrated into the PanEvolution platform to maximize their value in industrial applications.
{"title":"PanEvolution: Integrating CALPHAD, microstructure modeling, and finite element method","authors":"Weisheng Cao , Fan Zhang , Kamalnath Kadirvel , Shuanglin Chen , Eric Payton , Matthew Krug","doi":"10.1016/j.calphad.2025.102851","DOIUrl":"10.1016/j.calphad.2025.102851","url":null,"abstract":"<div><div>This paper introduces PanEvolution, a modeling platform that integrates CALPHAD, microstructure modeling, and finite element method (FEM). This work represents the third generation of Pandat software, designed to simulate the microstructure evolution of metallic materials during conventional manufacturing processes. The key features of PanEvolution include: (1) direct coupling of CALPHAD with various FEM software packages. This enables FEM packages to obtain accurate input of phase information for multi-component alloys and perform simulations of microstructure evolution for technically important metallic alloys, including precipitation, recrystallization, grain growth, and coarsening, during conventional manufacturing processes such as forging and rolling. (2) an open architecture that facilitates the easy replacement and swapping of fast-acting microstructure models. This enables microstructure evolution and property models developed by academia or industry to be easily integrated into the PanEvolution platform to maximize their value in industrial applications.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102851"},"PeriodicalIF":1.9,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144579832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The phase equilibria of the Co–Cr binary system were experimentally investigated across the whole composition range. Liquidus and solidus temperatures, measured up to 1800 °C using a differential thermal analyzer and differential scanning calorimeter, were slightly higher than those reported in the literature. The equilibrium compositions of two-phase alloys were analyzed using an electron probe microanalyzer, yielding reliable data regarding the γ(Co) + α(Cr) phase boundaries at high temperatures and ε(Co) + σ phase boundaries at low temperatures. Subsequently, a thermodynamic assessment of the Co–Cr binary system was performed using the CALPHAD technique, relying on our experimental data as well as thermodynamic property data from the literatures. The calculated Co–Cr phase diagram accurately reproduced the experimentally determined phase boundaries and thermodynamic properties, including activity, excess enthalpy, and excess Gibbs energy.
{"title":"Phase equilibria and thermodynamic assessment of the Co–Cr binary system","authors":"Kazushige Ioroi, Haruhi Kumeta, Xiao Xu, Ryosuke Kainuma, Toshihiro Omori","doi":"10.1016/j.calphad.2025.102853","DOIUrl":"10.1016/j.calphad.2025.102853","url":null,"abstract":"<div><div>The phase equilibria of the Co–Cr binary system were experimentally investigated across the whole composition range. Liquidus and solidus temperatures, measured up to 1800 °C using a differential thermal analyzer and differential scanning calorimeter, were slightly higher than those reported in the literature. The equilibrium compositions of two-phase alloys were analyzed using an electron probe microanalyzer, yielding reliable data regarding the γ(Co) + α(Cr) phase boundaries at high temperatures and ε(Co) + σ phase boundaries at low temperatures. Subsequently, a thermodynamic assessment of the Co–Cr binary system was performed using the CALPHAD technique, relying on our experimental data as well as thermodynamic property data from the literatures. The calculated Co–Cr phase diagram accurately reproduced the experimentally determined phase boundaries and thermodynamic properties, including activity, excess enthalpy, and excess Gibbs energy.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102853"},"PeriodicalIF":1.9,"publicationDate":"2025-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144570977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-04DOI: 10.1016/j.calphad.2025.102852
Kun Wang , Patrice Chartrand
The Modified Quasichemical Model in the Distinguishable-Pair Approximation (MQMDPA) was originally developed to describe thermodynamic properties of binary solutions with manifold short-range ordering (SRO) among atoms. This study extends the MQMDPA to multicomponent solutions through the development of an on-the-fly bond-energy formalism (OTFBEF). The OTFBEF employs interpolation functions to dynamically transform bond energy expressions from binary to ternary and higher-order multicomponent systems. By fixing the interpolation functions to specific values, the OTFBEF seamlessly reduces to traditional geometric methods, the generic method, or the hybrid Kohler-Toop loop framework, ensuring compatibility with established approaches, particularly with the widely used MQMPA. The interpolation functions can be optimized using experimental data from ternary systems or theoretically defined through integral and partial methods, providing flexibility for both prediction and calibration. The versatility and generality of the OTFBEF empower the MQMDPA to model multicomponent solutions with complex configurations effectively. Future work will focus on expanding the MQMDPA within a two-sublattice framework to address reciprocal solutions, further enhancing its applicability.
{"title":"Extension of the modified quasichemical model in the distinguishable-pair approximation to multicomponent solutions via an on-the-fly interpolation framework","authors":"Kun Wang , Patrice Chartrand","doi":"10.1016/j.calphad.2025.102852","DOIUrl":"10.1016/j.calphad.2025.102852","url":null,"abstract":"<div><div>The Modified Quasichemical Model in the Distinguishable-Pair Approximation (MQMDPA) was originally developed to describe thermodynamic properties of binary solutions with manifold short-range ordering (SRO) among atoms. This study extends the MQMDPA to multicomponent solutions through the development of an on-the-fly bond-energy formalism (OTFBEF). The OTFBEF employs interpolation functions to dynamically transform bond energy expressions from binary to ternary and higher-order multicomponent systems. By fixing the interpolation functions to specific values, the OTFBEF seamlessly reduces to traditional geometric methods, the generic method, or the hybrid Kohler-Toop loop framework, ensuring compatibility with established approaches, particularly with the widely used MQMPA. The interpolation functions can be optimized using experimental data from ternary systems or theoretically defined through integral and partial methods, providing flexibility for both prediction and calibration. The versatility and generality of the OTFBEF empower the MQMDPA to model multicomponent solutions with complex configurations effectively. Future work will focus on expanding the MQMDPA within a two-sublattice framework to address reciprocal solutions, further enhancing its applicability.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102852"},"PeriodicalIF":1.9,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-01DOI: 10.1016/j.calphad.2025.102854
Sinn-wen Chen , Te-Wei Lin , Hsin-Chieh Huang , Cheng-Hsi Ho , Chuan Zhang , Jun Zhu
The Sn–In–Ni–Zn system is an important material system for electronic soldering. Various alloys, such as Sn–In, Sn–Ni, Sn–Zn, and Sn–In–Zn, are frequently used in electronic products. Unexpectedly, it was found that even for these important systems, there are only limited experimental measurements of the liquidus and invariant reaction temperatures. Additionally, there are significant differences between the experimental results and those calculated using the CALPHAD method with various available databases. To tackle these issues, Sn-rich alloys including Sn–Zn, Sn–In, Sn–Ni, Sn–In–Zn, Sn–Ni–Zn, Sn–In–Ni, and Sn–In–Ni–Zn were prepared. Their liquidus temperatures were determined experimentally through thermal analysis combined with holding-quenching experiments, while invariant reaction temperatures were measured using thermal analysis with an internal marker. The uncertainties in the measurements are 3 °C for the liquidus temperatures and 1 °C for the invariant reactions. Although high-quality thermal analysis can determine phase transformation temperatures with an accuracy of up to 1 °C, reliable determination of liquidus temperatures becomes quite challenging when the heat effect is not significant. This may explain why the literature data are inconsistent. These experimental results were subsequently used to refine CALPHAD-type modeling, and phase diagram calculations with better agreement were achieved.
{"title":"Phase transformation temperatures of the Sn–In–Ni–Zn quaternary system","authors":"Sinn-wen Chen , Te-Wei Lin , Hsin-Chieh Huang , Cheng-Hsi Ho , Chuan Zhang , Jun Zhu","doi":"10.1016/j.calphad.2025.102854","DOIUrl":"10.1016/j.calphad.2025.102854","url":null,"abstract":"<div><div>The Sn–In–Ni–Zn system is an important material system for electronic soldering. Various alloys, such as Sn–In, Sn–Ni, Sn–Zn, and Sn–In–Zn, are frequently used in electronic products. Unexpectedly, it was found that even for these important systems, there are only limited experimental measurements of the liquidus and invariant reaction temperatures. Additionally, there are significant differences between the experimental results and those calculated using the CALPHAD method with various available databases. To tackle these issues, Sn-rich alloys including Sn–Zn, Sn–In, Sn–Ni, Sn–In–Zn, Sn–Ni–Zn, Sn–In–Ni, and Sn–In–Ni–Zn were prepared. Their liquidus temperatures were determined experimentally through thermal analysis combined with holding-quenching experiments, while invariant reaction temperatures were measured using thermal analysis with an internal marker. The uncertainties in the measurements are 3 °C for the liquidus temperatures and 1 °C for the invariant reactions. Although high-quality thermal analysis can determine phase transformation temperatures with an accuracy of up to 1 °C, reliable determination of liquidus temperatures becomes quite challenging when the heat effect is not significant. This may explain why the literature data are inconsistent. These experimental results were subsequently used to refine CALPHAD-type modeling, and phase diagram calculations with better agreement were achieved.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102854"},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-30DOI: 10.1016/j.calphad.2025.102855
Amedeo Morsa , Elena Yazhenskikh , Mirko Ziegner , Egbert Wessel , Rhys Dominic Jacob , Michael Müller , Dmitry Sergeev
This work presents a comprehensive experimental investigation into the thermal properties of the binary system MgSO4-CaSO4, alongside thermodynamic modelling of its thermodynamic properties, with a focus on enhancing its application in thermal energy storage. The phase diagram and thermodynamic properties of the pure sulphates and intermediate compounds were determined using Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC). The DSC results led to the refinement of the enthalpy values for phase transitions of MgSO4, with updated values of 14.6 kJ/mol and 43.4 kJ/mol for the solid-solid and solid-liquid transitions, respectively. High-Temperature X-ray Diffraction (HTXRD) was employed to study the intermediate compounds, leading to the identification of CaMg2(SO4)3. For the first time, the melting temperature and the enthalpy of fusion for this compound were experimentally determined, yielding a value of 145.5 kJ/mol at 1213 ± 5 °C. A novel phase with the composition CaMg(SO4)2 was identified using DTA, HTXRD, and Scanning Electron Microscopy (SEM). This phase exhibits a melting temperature of 1309 ± 5 °C, as determined by DTA, and demonstrates thermal stability within a high-temperature range of 1020–1308 °C. These experimental data were used to update the thermodynamic database for the system MgSO4-CaSO4 for more accurate thermochemical calculations and predictions.
{"title":"Experimental study and thermodynamic assessment of the MgSO4-CaSO4 system","authors":"Amedeo Morsa , Elena Yazhenskikh , Mirko Ziegner , Egbert Wessel , Rhys Dominic Jacob , Michael Müller , Dmitry Sergeev","doi":"10.1016/j.calphad.2025.102855","DOIUrl":"10.1016/j.calphad.2025.102855","url":null,"abstract":"<div><div>This work presents a comprehensive experimental investigation into the thermal properties of the binary system MgSO<sub>4</sub>-CaSO<sub>4</sub>, alongside thermodynamic modelling of its thermodynamic properties, with a focus on enhancing its application in thermal energy storage. The phase diagram and thermodynamic properties of the pure sulphates and intermediate compounds were determined using Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC). The DSC results led to the refinement of the enthalpy values for phase transitions of MgSO<sub>4</sub>, with updated values of 14.6 kJ/mol and 43.4 kJ/mol for the solid-solid and solid-liquid transitions, respectively. High-Temperature X-ray Diffraction (HTXRD) was employed to study the intermediate compounds, leading to the identification of CaMg<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>. For the first time, the melting temperature and the enthalpy of fusion for this compound were experimentally determined, yielding a value of 145.5 kJ/mol at 1213 ± 5 °C. A novel phase with the composition CaMg(SO<sub>4</sub>)<sub>2</sub> was identified using DTA, HTXRD, and Scanning Electron Microscopy (SEM). This phase exhibits a melting temperature of 1309 ± 5 °C, as determined by DTA, and demonstrates thermal stability within a high-temperature range of 1020–1308 °C. These experimental data were used to update the thermodynamic database for the system MgSO<sub>4</sub>-CaSO<sub>4</sub> for more accurate thermochemical calculations and predictions.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102855"},"PeriodicalIF":1.9,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-26DOI: 10.1016/j.calphad.2025.102848
Jesus A. Arias Hernandez, Elmira Moosavi-Khoonsari
Thermodynamic modeling of oxidic systems is crucial in advancing various fields of science and technology. Polyhedron Model (PM) estimates the standard enthalpy of formation and entropy of mixed oxides via the linear summation of the thermodynamic properties of constituent polyhedra. Each polyhedron consists of a centered cation with neighboring oxygen anions; hence, the model accounts for the interaction between anions and cations. While second-order transitions have been considered in previous iterations of the model, the PM has certain shortcomings, including neglect of variations in polyhedron volume, polyhedron distortion, inter-polyhedron linkage, and second nearest-neighbor or higher-order interactions, which are not negligible. The present work introduces the Modified Polyhedron Model (MPM), which aims to incorporate these contributions through a neural network (NN) model to improve the accuracy of predictions for standard enthalpy of formation () and standard entropy (). This is possible by using the residuals from the PM as inputs to the NN model, whose outputs are the calculated thermodynamic properties of compounds. The dataset consists of 155 compounds in the Li-Na-K-Ca-Mg-Mn-Fe-Al-Ti-Si-O system, classified by 20 polyhedra. The MPM considerably reduces the error in predicting enthalpy of formation and entropy, improving the alignment with experimental values across most analyzed compounds in comparison with the PM. These results suggest that the MPM can significantly improve the predictability of thermodynamic properties for mixed oxides.
{"title":"Modified polyhedron model for predicting standard enthalpy of formation and entropy of mixed oxides","authors":"Jesus A. Arias Hernandez, Elmira Moosavi-Khoonsari","doi":"10.1016/j.calphad.2025.102848","DOIUrl":"10.1016/j.calphad.2025.102848","url":null,"abstract":"<div><div>Thermodynamic modeling of oxidic systems is crucial in advancing various fields of science and technology. Polyhedron Model (PM) estimates the standard enthalpy of formation and entropy of mixed oxides via the linear summation of the thermodynamic properties of constituent polyhedra. Each polyhedron consists of a centered cation with neighboring oxygen anions; hence, the model accounts for the interaction between anions and cations. While second-order transitions have been considered in previous iterations of the model, the PM has certain shortcomings, including neglect of variations in polyhedron volume, polyhedron distortion, inter-polyhedron linkage, and second nearest-neighbor or higher-order interactions, which are not negligible. The present work introduces the Modified Polyhedron Model (MPM), which aims to incorporate these contributions through a neural network (NN) model to improve the accuracy of predictions for standard enthalpy of formation (<span><math><mrow><msubsup><mrow><mo>Δ</mo><mi>H</mi></mrow><mrow><mn>298</mn><mspace></mspace><mi>K</mi></mrow><mi>o</mi></msubsup></mrow></math></span>) and standard entropy (<span><math><mrow><msubsup><mi>S</mi><mrow><mn>298</mn><mspace></mspace><mi>K</mi></mrow><mi>o</mi></msubsup></mrow></math></span>). This is possible by using the residuals from the PM as inputs to the NN model, whose outputs are the calculated thermodynamic properties of compounds. The dataset consists of 155 compounds in the Li-Na-K-Ca-Mg-Mn-Fe-Al-Ti-Si-O system, classified by 20 polyhedra. The MPM considerably reduces the error in predicting enthalpy of formation and entropy, improving the alignment with experimental values across most analyzed compounds in comparison with the PM. These results suggest that the MPM can significantly improve the predictability of thermodynamic properties for mixed oxides.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102848"},"PeriodicalIF":1.9,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144489490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We conducted an analysis of the crystal structure and thermodynamic properties of CaV2O4 synthesized through high-temperature solid-state calcination under elevated temperature conditions. The XRD analysis indicated that CaV2O4 crystallizes in an orthorhombic structure, characterized by unit cell parameters a = 9.21311(10) Å, b = 3.008421(35) Å, c = 10.68206(12) Å, and α = β = γ = 90°. The enthalpy of formation and entropy of CaV2O4 at 298.15 K are −1890.56 ± 5.84 kJ/mol J·mol−1 and 129.62 ± 1.09 J·mol−1 K−1, respectively. The heat capacity of CaV2O4 at 573–1373 K was determined using drop calorimetry, yielding the expression Cp = 165.7748 + 3.2353 × 10−2T - 2.64268 × 106T−2 (J·mol−1·K−1). Additional thermodynamic data for CaV2O4 were derived using the Cp,m expression at elevated temperatures.
{"title":"Crystal structure and thermodynamic properties of post-spinel-type CaV2O4 at high temperatures (298.15–1373 K)","authors":"Dapeng Zhong , Jie Yu , Xin Jin , Guishang Pei , Wenhao Yu , Qingyun Huang , Changcai Zhou , Xuewei Lv , Wei Lv","doi":"10.1016/j.calphad.2025.102850","DOIUrl":"10.1016/j.calphad.2025.102850","url":null,"abstract":"<div><div>We conducted an analysis of the crystal structure and thermodynamic properties of CaV<sub>2</sub>O<sub>4</sub> synthesized through high-temperature solid-state calcination under elevated temperature conditions. The XRD analysis indicated that CaV<sub>2</sub>O<sub>4</sub> crystallizes in an orthorhombic structure, characterized by unit cell parameters <em>a</em> = 9.21311(10) Å, <em>b</em> = 3.008421(35) Å, <em>c</em> = 10.68206(12) Å, and <em>α</em> = <em>β</em> = <em>γ</em> = 90°. The enthalpy of formation and entropy of CaV<sub>2</sub>O<sub>4</sub> at 298.15 K are −1890.56 ± 5.84 kJ/mol J·mol<sup>−1</sup> and 129.62 ± 1.09 J·mol<sup>−1</sup> K<sup>−1</sup>, respectively. The heat capacity of CaV<sub>2</sub>O<sub>4</sub> at 573–1373 K was determined using drop calorimetry, yielding the expression <em>C</em><sub><em>p</em></sub> = 165.7748 + 3.2353 × 10<sup>−2</sup><em>T</em> - 2.64268 × 10<sup>6</sup><em>T</em><sup>−2</sup> (J·mol<sup>−1</sup>·K<sup>−1</sup>). Additional thermodynamic data for CaV<sub>2</sub>O<sub>4</sub> were derived using the <em>C</em><sub><em>p,m</em></sub> expression at elevated temperatures.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102850"},"PeriodicalIF":1.9,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144331373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-09DOI: 10.1016/j.calphad.2025.102839
Jin Tao , Rui Zhang , Yuhan Wang , Zewei Chen , Shitao Zhang , Caimin Huang , Qianxin Long , Zhao Lu , Like Tao , Qingrong Yao , Jiang Wang
In this study, thermodynamic optimization of the Er-Si binary system was performed using the CALPHAD method. The calculated phase diagram showed good consistency with existing experimental data. Furthermore, the phase equilibrium of the Al-Si-Er ternary system was investigated via electron probe microanalysis (EPMA) and X-ray diffraction (XRD), building on prior experimental data. Based on the experimental results obtained in this work and literature reports, the thermodynamic parameters of the Al-Si-Er ternary system were optimized. Both calculated isothermal cross section at 600 °C and the vertical cross section along Al70Si30-Al70Er30 (at. %) in the ternary system are in agreement with experimental data, indicating reliability of the thermodynamic description. This work provides essential foundational data for the development of high-performance rare earth Al-Si-Er alloys.
{"title":"Experimental investigation and thermodynamic description of binary Er-Si and ternary Al-Si-Er systems","authors":"Jin Tao , Rui Zhang , Yuhan Wang , Zewei Chen , Shitao Zhang , Caimin Huang , Qianxin Long , Zhao Lu , Like Tao , Qingrong Yao , Jiang Wang","doi":"10.1016/j.calphad.2025.102839","DOIUrl":"10.1016/j.calphad.2025.102839","url":null,"abstract":"<div><div>In this study, thermodynamic optimization of the Er-Si binary system was performed using the CALPHAD method. The calculated phase diagram showed good consistency with existing experimental data. Furthermore, the phase equilibrium of the Al-Si-Er ternary system was investigated via electron probe microanalysis (EPMA) and X-ray diffraction (XRD), building on prior experimental data. Based on the experimental results obtained in this work and literature reports, the thermodynamic parameters of the Al-Si-Er ternary system were optimized. Both calculated isothermal cross section at 600 °C and the vertical cross section along Al<sub>70</sub>Si<sub>30</sub>-Al<sub>70</sub>Er<sub>30</sub> (at. %) in the ternary system are in agreement with experimental data, indicating reliability of the thermodynamic description. This work provides essential foundational data for the development of high-performance rare earth Al-Si-Er alloys.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102839"},"PeriodicalIF":1.9,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144243397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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