Pub Date : 2025-09-01Epub Date: 2025-08-27DOI: 10.1016/j.calphad.2025.102867
Stuart C. Ness , Tucker Moore , Steve Kilczewski , Kristopher Behler , Matthew Dunstan , Scott J. McCormack
Oxide-Melt Solution Calorimetry (OMSC) has been used to investigate standard enthalpies of formation in transition metal diborides, a first for the technique. Formation enthalpies for the Group IV and Group V transition metal diborides have been measured (TiB2: ΔfH⦵ = −280 ± 11 kJ/mol, ZrB2: ΔfH⦵ = −328 ± 10 kJ/mol, NbB2: ΔfH⦵ = −245 ± 12 kJ/mol, HfB2: ΔfH⦵ = −336 ± 11 kJ/mol, TaB2: ΔfH⦵ = −195 ± 25 kJ/mol) and compared with good agreement to literature values. Multiple thermochemical pathway confirmations are reported. This data is required for the development of robust diboride phase diagrams for ultra-high temperature applications.
{"title":"Development of oxide melt solution calorimetry for transition metal diborides","authors":"Stuart C. Ness , Tucker Moore , Steve Kilczewski , Kristopher Behler , Matthew Dunstan , Scott J. McCormack","doi":"10.1016/j.calphad.2025.102867","DOIUrl":"10.1016/j.calphad.2025.102867","url":null,"abstract":"<div><div>Oxide-Melt Solution Calorimetry (OMSC) has been used to investigate standard enthalpies of formation in transition metal diborides, a first for the technique. Formation enthalpies for the Group IV and Group V transition metal diborides have been measured (TiB<sub>2</sub>: Δ<sub>f</sub>H<sup>⦵</sup> = −280 ± 11 kJ/mol, ZrB<sub>2</sub>: Δ<sub>f</sub>H<sup>⦵</sup> = −328 ± 10 kJ/mol, NbB<sub>2</sub>: Δ<sub>f</sub>H<sup>⦵</sup> = −245 ± 12 kJ/mol, HfB<sub>2</sub>: Δ<sub>f</sub>H<sup>⦵</sup> = −336 ± 11 kJ/mol, TaB<sub>2</sub>: Δ<sub>f</sub>H<sup>⦵</sup> = −195 ± 25 kJ/mol) and compared with good agreement to literature values. Multiple thermochemical pathway confirmations are reported. This data is required for the development of robust diboride phase diagrams for ultra-high temperature applications.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102867"},"PeriodicalIF":1.9,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144904505","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":"2025-09-01","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 : 2025-09-01Epub 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":"2025-09-01","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}
Pub Date : 2025-09-01Epub Date: 2025-07-28DOI: 10.1016/j.calphad.2025.102861
Tuan-Minh Vu , Caroline Toffolon-Masclet , Jean-Marc Joubert
The thermodynamic assessments of the two ternary Cr–H–Zr and Fe–H–Zr systems are carried out using the CALPHAD approach. The hydrogenation properties of all the intermetallic compounds of these two systems are assessed. The formation enthalpies of the E1a-Zr3FeH7 and -Zr2FeH5 hydrides are evaluated by DFT calculations. The Pressure-Composition-Temperature diagrams of the Zr(CrxFe1-x)2 (0.4 < x < 1.1) of the C14 Laves phase are optimized. The calculations and optimization are carried out under para-equilibrium conditions in which the complete system was treated like a pseudo-binary system.
{"title":"Thermodynamic assessment of the quaternary Cr–Fe–H–Zr system","authors":"Tuan-Minh Vu , Caroline Toffolon-Masclet , Jean-Marc Joubert","doi":"10.1016/j.calphad.2025.102861","DOIUrl":"10.1016/j.calphad.2025.102861","url":null,"abstract":"<div><div>The thermodynamic assessments of the two ternary Cr–H–Zr and Fe–H–Zr systems are carried out using the CALPHAD approach. The hydrogenation properties of all the intermetallic compounds of these two systems are assessed. The formation enthalpies of the <em>E</em>1<em>a</em>-Zr<sub>3</sub>FeH<sub>7</sub> and <span><math><mrow><mi>C</mi><mn>16</mn></mrow></math></span>-Zr<sub>2</sub>FeH<sub>5</sub> hydrides are evaluated by DFT calculations. The Pressure-Composition-Temperature diagrams of the Zr(Cr<sub>x</sub>Fe<sub>1-x</sub>)<sub>2</sub> (0.4 < x < 1.1) of the <em>C</em>14 Laves phase are optimized. The calculations and optimization are carried out under para-equilibrium conditions in which the complete system was treated like a pseudo-binary system.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102861"},"PeriodicalIF":1.9,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714307","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 : 2025-09-01Epub 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":"2025-09-01","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}
This work determined the isothermal sections of the Fe-Co-W system at 1273 K and 1073 K using the equilibrated alloy method. The solubility ranges of the μ-(Fe,Co)7W6, λ-Fe2W, and Co3W compounds in the Fe-Co-W ternary system were identified. No new ternary compounds were observed. Based on existing experimental data, a thermodynamic optimization of the Fe-Co-W ternary system and related binary systems was conducted. The (A)4(A,B)2(A,B)1(A,B)6 lattice model was employed to describe the μ-(Co,Fe)7W6 compound, and the thermodynamic database of the Co-W binary system was re-assessed. A new thermodynamic database for the Fe-Co-W system was established, demonstrating high consistency with the experimental data.
{"title":"Experimental investigation and thermodynamic re-assessment of the Fe-Co-W phase diagram","authors":"C.B. Li, Z.Q. Wang, L.D. Ye, J.F. Wu, K.G. Wang, L.B. Liu, L.G. Zhang","doi":"10.1016/j.calphad.2025.102856","DOIUrl":"10.1016/j.calphad.2025.102856","url":null,"abstract":"<div><div>This work determined the isothermal sections of the Fe-Co-W system at 1273 K and 1073 K using the equilibrated alloy method. The solubility ranges of the μ-(Fe,Co)<sub>7</sub>W<sub>6</sub>, λ-Fe<sub>2</sub>W, and Co<sub>3</sub>W compounds in the Fe-Co-W ternary system were identified. No new ternary compounds were observed. Based on existing experimental data, a thermodynamic optimization of the Fe-Co-W ternary system and related binary systems was conducted. The (A)<sub>4</sub>(A,B)<sub>2</sub>(A,B)<sub>1</sub>(A,B)<sub>6</sub> lattice model was employed to describe the μ-(Co,Fe)<sub>7</sub>W<sub>6</sub> compound, and the thermodynamic database of the Co-W binary system was re-assessed. A new thermodynamic database for the Fe-Co-W system was established, demonstrating high consistency with the experimental data.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102856"},"PeriodicalIF":1.9,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144655015","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 : 2025-09-01Epub Date: 2025-08-05DOI: 10.1016/j.calphad.2025.102864
Jiulong Hang , Xiumin Chen , Yi Lu , Tianao Zhang , Dongping Tao
The key binary parameters of solution thermodynamic models are usually determined by the measured activity data of binary solutions, and then thermodynamic properties of the relevant ternary or even multi-component solutions can be predicted. However, in the absence of experimental data, it is currently still difficult and challenging to determine these parameters reliably. In this paper, the partial radial distribution functions (PRDF) of 9 binary liquid alloys are obtained by ab initio molecular dynamics (AIMD) simulation. Based on the statistical average principle of physical quantities, a simplified expression of the average pair potential energy (APPE) of fluid molecules with PRDF is correctly derived. Then it can be correlated with the binary model parameters of the Regular Solution Model (RSM), the Wilson equation, the Non-Random Two-Liquid equation (NRTL), and the Molecular Interaction Volume Model (MIVM), and their values are determined. Based on this, the component activities of the 9 binary as well as the 4 ternary liquid alloys systems were estimated and compared with those obtained by the fitting parameter method and the Miedema model. The results show that for the 9 binary alloys systems, when the symmetric PRDF method is used, the standard deviation (SD) and the average relative deviation (ARD) of Wilson equation are 0.073 and 25 % respectively; when the asymmetric PRDF method is used, the SD and ARD of RSM are 0.067 and 15 %; when the fitting parameter method is used, the SD and ARD of Wilson equation are 0.016 and 4 %; when the Miedema model is used, its SD and ARD are 0.090 and 35 %, respectively. For the 4 ternary alloys systems, when the symmetric method is used, the SD and ARD of Wilson equation are 0.068 and 16 % respectively; when the asymmetric method is used, the SD and ARD of RSM are 0.061 and 14 %; when the fitting parameter method is used, the SD and ARD of MIVM are 0.028 and 6 %; when the combined method of the Miedema model and the Toop model is used, its SD and ARD are 0.052 and 13 %, respectively. This indicates that the simplified expression of APPE related with PRDF can be used to obtain the key binary parameters of some thermodynamic models for estimating all component activities of ternary or even multi-component liquid alloys in the absence of activity experimental data of binary liquid alloys.
{"title":"Estimation of component activities of ternary liquid alloys by partial radial distribution functions of binary liquid alloys obtained from ab initio molecular dynamics simulation","authors":"Jiulong Hang , Xiumin Chen , Yi Lu , Tianao Zhang , Dongping Tao","doi":"10.1016/j.calphad.2025.102864","DOIUrl":"10.1016/j.calphad.2025.102864","url":null,"abstract":"<div><div>The key binary parameters of solution thermodynamic models are usually determined by the measured activity data of binary solutions, and then thermodynamic properties of the relevant ternary or even multi-component solutions can be predicted. However, in the absence of experimental data, it is currently still difficult and challenging to determine these parameters reliably. In this paper, the partial radial distribution functions (PRDF) of 9 binary liquid alloys are obtained by ab initio molecular dynamics (AIMD) simulation. Based on the statistical average principle of physical quantities, a simplified expression of the average pair potential energy (APPE) of fluid molecules with PRDF is correctly derived. Then it can be correlated with the binary model parameters of the Regular Solution Model (RSM), the Wilson equation, the Non-Random Two-Liquid equation (NRTL), and the Molecular Interaction Volume Model (MIVM), and their values are determined. Based on this, the component activities of the 9 binary as well as the 4 ternary liquid alloys systems were estimated and compared with those obtained by the fitting parameter method and the Miedema model. The results show that for the 9 binary alloys systems, when the symmetric PRDF method is used, the standard deviation (SD) and the average relative deviation (ARD) of Wilson equation are 0.073 and 25 % respectively; when the asymmetric PRDF method is used, the SD and ARD of RSM are 0.067 and 15 %; when the fitting parameter method is used, the SD and ARD of Wilson equation are 0.016 and 4 %; when the Miedema model is used, its SD and ARD are 0.090 and 35 %, respectively. For the 4 ternary alloys systems, when the symmetric method is used, the SD and ARD of Wilson equation are 0.068 and 16 % respectively; when the asymmetric method is used, the SD and ARD of RSM are 0.061 and 14 %; when the fitting parameter method is used, the SD and ARD of MIVM are 0.028 and 6 %; when the combined method of the Miedema model and the Toop model is used, its SD and ARD are 0.052 and 13 %, respectively. This indicates that the simplified expression of APPE related with PRDF can be used to obtain the key binary parameters of some thermodynamic models for estimating all component activities of ternary or even multi-component liquid alloys in the absence of activity experimental data of binary liquid alloys.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102864"},"PeriodicalIF":1.9,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144770603","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 : 2025-09-01Epub Date: 2025-08-13DOI: 10.1016/j.calphad.2025.102865
Guangcheng Xiao, Kaige Wang, Lideng Ye, Yueyan Tian, Jifeng Yang, Ligang Zhang, Libin Liu
Based on experimental data measured by scanning electron microscope (SEM), X-ray diffraction (XRD) and electron probe microanalysis (EPMA), isothermal sections of Ti-Al-Hf at 900 °C and 1100 °C were established. A total of four three-phase regions and eight two-phase regions were found at the two temperatures, and a ternary compound τ was also found. The maximum solubility of Ti2Al5 for Hf at 900 °C was obtained, and the maximum solubility of binary compounds TiAl, TiAl2, HfAl2, Hf2Al for the third element and Al, Hf, Ti in the τ phase was also measured. Based on the experimental data, the thermodynamic evaluation of the Ti-Al-Hf system was carried out using the CALPHAD(CALculation of PHAse Diagrams) method for two isothermal sections. The liquid phase, Bcc phase and Hcp phase were modeled using the substitutional solution model, and the ternary phase τ was treated as a stoichiometric compound. Its thermodynamic model was defined as (Hf)2(Al)2(Ti)1. The final calculation results were in good agreement with the experimental results, including phase equilibrium and alloy composition.
{"title":"Experiment investigation and thermodynamic assessment of the ternary Ti-Al-Hf system","authors":"Guangcheng Xiao, Kaige Wang, Lideng Ye, Yueyan Tian, Jifeng Yang, Ligang Zhang, Libin Liu","doi":"10.1016/j.calphad.2025.102865","DOIUrl":"10.1016/j.calphad.2025.102865","url":null,"abstract":"<div><div>Based on experimental data measured by scanning electron microscope (SEM), X-ray diffraction (XRD) and electron probe microanalysis (EPMA), isothermal sections of Ti-Al-Hf at 900 °C and 1100 °C were established. A total of four three-phase regions and eight two-phase regions were found at the two temperatures, and a ternary compound τ was also found. The maximum solubility of Ti<sub>2</sub>Al<sub>5</sub> for Hf at 900 °C was obtained, and the maximum solubility of binary compounds TiAl, TiAl<sub>2</sub>, HfAl<sub>2</sub>, Hf<sub>2</sub>Al for the third element and Al, Hf, Ti in the τ phase was also measured. Based on the experimental data, the thermodynamic evaluation of the Ti-Al-Hf system was carried out using the CALPHAD(CALculation of PHAse Diagrams) method for two isothermal sections. The liquid phase, Bcc phase and Hcp phase were modeled using the substitutional solution model, and the ternary phase τ was treated as a stoichiometric compound. Its thermodynamic model was defined as (Hf)<sub>2</sub>(Al)<sub>2</sub>(Ti)<sub>1</sub>. The final calculation results were in good agreement with the experimental results, including phase equilibrium and alloy composition.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102865"},"PeriodicalIF":1.9,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144828272","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 : 2025-09-01Epub 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":"2025-09-01","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}
Pub Date : 2025-09-01Epub Date: 2025-07-25DOI: 10.1016/j.calphad.2025.102860
Shu Li , Wenjie Wei , Boya Zhang , Zhanmin Cao
A comprehensive review and evaluation of the phase equilibrium and thermodynamic properties of the Sb-O system across its entire compositional range was provided. Controversial issues were addressed through additional experimental studies, including the transition temperatures between the α and β phases of Sb2O3, the eutectic temperature of β-Sb2O3 and α-Sb2O4 to liquid, and the decomposition products of Sb6O13. Using the CALPHAD method, the liquid phase and three stable antimony oxides (Sb2O3, Sb2O4, and Sb6O13) were modeled. The liquid phase, from metallic liquid to oxide melt, is described by a modified Quasichemical model that accounts for the strong short-range order in the oxide liquid at the Sb2O3 composition. The final established Sb-O phase diagram at 1 atm, which can accurately reproduce all available thermodynamic and phase equilibrium data, is presented.
{"title":"Phase diagram and thermodynamic modeling of the Sb-O system","authors":"Shu Li , Wenjie Wei , Boya Zhang , Zhanmin Cao","doi":"10.1016/j.calphad.2025.102860","DOIUrl":"10.1016/j.calphad.2025.102860","url":null,"abstract":"<div><div>A comprehensive review and evaluation of the phase equilibrium and thermodynamic properties of the Sb-O system across its entire compositional range was provided. Controversial issues were addressed through additional experimental studies, including the transition temperatures between the α and β phases of Sb<sub>2</sub>O<sub>3</sub>, the eutectic temperature of β-Sb<sub>2</sub>O<sub>3</sub> and α-Sb<sub>2</sub>O<sub>4</sub> to liquid, and the decomposition products of Sb<sub>6</sub>O<sub>13</sub>. Using the CALPHAD method, the liquid phase and three stable antimony oxides (Sb<sub>2</sub>O<sub>3</sub>, Sb<sub>2</sub>O<sub>4</sub>, and Sb<sub>6</sub>O<sub>13</sub>) were modeled. The liquid phase, from metallic liquid to oxide melt, is described by a modified Quasichemical model that accounts for the strong short-range order in the oxide liquid at the Sb<sub>2</sub>O<sub>3</sub> composition. The final established Sb-O phase diagram at 1 atm, which can accurately reproduce all available thermodynamic and phase equilibrium data, is presented.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102860"},"PeriodicalIF":1.9,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144702609","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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