Pub Date : 2025-08-22DOI: 10.1016/j.calphad.2025.102866
Weifeng Cheng , Jiang Wang , Qingrong Yao , Qing Chen , Guanghui Rao , Huaiying Zhou
The phase equilibria of the Y-Fe-B ternary system were investigated using scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD). Six ternary intermetallic compounds were identified through SEM-EDS analysis and XRD Rietveld refinements: Y2Fe14B (Nd2Fe14B-type structure and space group P42/mnm), YFe4B4 (Nd1+ϵFe4B4-type structure and space group Pccn), YFe2B2 (CeAl2Ga2-type structure and space group I4/mmm), YFeB4 (YCrB4-type structure and space group Pbam), Y5Fe2B6 (Pr5Co2B6-type structure and space group R-3m) and Y3FeB7 (Y3ReB7-type structure and space group Cmcm). The solidification microstructure, phase compositions and phase transitions of YxFe94-xB6 and Y11.7Fe88.3-xBx as-cast alloys were examined using SEM-EDS and differential scanning calorimetry (DSC). Furthermore, by integrating the previous calculations of the Y-Fe and Fe-B binary systems with the results determined in this study and reported in the literature, thermodynamic calculation of the Y-Fe-B ternary system was conducted by means of the CALPHAD method, based on the present optimization of the Y-B binary system. The calculated phase diagrams and thermodynamic properties of the Y-B binary system are in good agreement with the reported results, while the calculated vertical and isothermal sections of the Y-Fe-B ternary system are consistent with the experimental data. Finally, the available thermodynamic parameters for the Y-Fe-B ternary system were obtained, providing a robust foundation to develop a thermodynamic database of magnetic RE-Fe-B-based alloys.
{"title":"Phase equilibria, phase structure and phase transition of Y-Fe-B alloys: Experimental investigation and thermodynamic calculation","authors":"Weifeng Cheng , Jiang Wang , Qingrong Yao , Qing Chen , Guanghui Rao , Huaiying Zhou","doi":"10.1016/j.calphad.2025.102866","DOIUrl":"10.1016/j.calphad.2025.102866","url":null,"abstract":"<div><div>The phase equilibria of the Y-Fe-B ternary system were investigated using scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD). Six ternary intermetallic compounds were identified through SEM-EDS analysis and XRD Rietveld refinements: Y<sub>2</sub>Fe<sub>14</sub>B (Nd<sub>2</sub>Fe<sub>14</sub>B-type structure and space group <em>P</em>4<sub><em>2</em></sub><em>/mnm</em>), YFe<sub>4</sub>B<sub>4</sub> (Nd<sub>1+ϵ</sub>Fe<sub>4</sub>B<sub>4</sub>-type structure and space group <em>Pccn</em>), YFe<sub>2</sub>B<sub>2</sub> (CeAl<sub>2</sub>Ga<sub>2</sub>-type structure and space group <em>I</em><em>4</em><em>/mmm</em>), YFeB<sub>4</sub> (YCrB<sub>4</sub>-type structure and space group <em>Pbam</em>), Y<sub>5</sub>Fe<sub>2</sub>B<sub>6</sub> (Pr<sub>5</sub>Co<sub>2</sub>B<sub>6</sub>-type structure and space group <em>R-3m</em>) and Y<sub>3</sub>FeB<sub>7</sub> (Y<sub>3</sub>ReB<sub>7</sub>-type structure and space group <em>Cmcm</em>). The solidification microstructure, phase compositions and phase transitions of Y<sub><em>x</em></sub>Fe<sub>94-<em>x</em></sub>B<sub>6</sub> and Y<sub>11.7</sub>Fe<sub>88.3-<em>x</em></sub>B<sub><em>x</em></sub> as-cast alloys were examined using SEM-EDS and differential scanning calorimetry (DSC). Furthermore, by integrating the previous calculations of the Y-Fe and Fe-B binary systems with the results determined in this study and reported in the literature, thermodynamic calculation of the Y-Fe-B ternary system was conducted by means of the CALPHAD method, based on the present optimization of the Y-B binary system. The calculated phase diagrams and thermodynamic properties of the Y-B binary system are in good agreement with the reported results, while the calculated vertical and isothermal sections of the Y-Fe-B ternary system are consistent with the experimental data. Finally, the available thermodynamic parameters for the Y-Fe-B ternary system were obtained, providing a robust foundation to develop a thermodynamic database of magnetic RE-Fe-B-based alloys.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102866"},"PeriodicalIF":1.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144889780","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 : 2025-08-13DOI: 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":"2025-08-13","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 : 2025-08-05DOI: 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":"2025-08-05","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 : 2025-07-31DOI: 10.1016/j.calphad.2025.102863
Shumei Chen , Xukun Peng , Chunfa Liao , Xinyu Wu , Xu Wang , Liqing Li , Jinwanxiang Liu , Yunfen Jiao
The ionic behavior in the LiF-PrF3-Pr6O11 melt system is of critical importance for the praseodymium reduction process. This study investigates the effects of the LiF/PrF3 molar ratio (CR, n(LiF)/n(PrF3)) and temperature on the ionic species and their concentrations in melt through quantum chemical calculations and thermodynamic analysis. The results indicate that in the LiF-PrF3 melt, the dominant anions are [PrF4]-, [PrF6]3-, [PrF7]4-, [Pr2F7]- and F−. As the CR increases, the melt tends to form [PrFx]3−x anions with higher fluoride coordination numbers. With rising temperature, the complex ions in the melt transform into simpler ionic species. Upon dissolving of Pr6O11 in the LiF-PrF3 melt, the predominant anionic species formed are [PrOF6]5-, [Pr2OF5]-, [Pr2OF8]4-, [Pr2OF9]5- and [Pr2OF10]6-. An increase in CR promotes the transformation of [Pr2OFx]4−x anions into structures with higher fluoride coordination numbers. Simultaneously, the content of [PrOF6]5- anions increases progressively, and when the CR exceeds 3, [PrOF6]5- becomes the dominant anionic species in the melt. Increasing the melt temperature inhibits the coordination reactions of [Pr2OFx]4−x anions and accelerates their dissociation into [PrOFx]1−x anions.
{"title":"Thermodynamic investigation on ion structure of LiF-PrF3-Pr6O11 melt","authors":"Shumei Chen , Xukun Peng , Chunfa Liao , Xinyu Wu , Xu Wang , Liqing Li , Jinwanxiang Liu , Yunfen Jiao","doi":"10.1016/j.calphad.2025.102863","DOIUrl":"10.1016/j.calphad.2025.102863","url":null,"abstract":"<div><div>The ionic behavior in the LiF-PrF<sub>3</sub>-Pr<sub>6</sub>O<sub>11</sub> melt system is of critical importance for the praseodymium reduction process. This study investigates the effects of the LiF/PrF<sub>3</sub> molar ratio (CR, <em>n</em>(LiF)/<em>n</em>(PrF<sub>3</sub>)) and temperature on the ionic species and their concentrations in melt through quantum chemical calculations and thermodynamic analysis. The results indicate that in the LiF-PrF<sub>3</sub> melt, the dominant anions are [PrF<sub>4</sub>]<sup>-</sup>, [PrF<sub>6</sub>]<sup>3-</sup>, [PrF<sub>7</sub>]<sup>4-</sup>, [Pr<sub>2</sub>F<sub>7</sub>]<sup>-</sup> and F<sup>−</sup>. As the CR increases, the melt tends to form [PrF<sub>x</sub>]<sup>3−x</sup> anions with higher fluoride coordination numbers. With rising temperature, the complex ions in the melt transform into simpler ionic species. Upon dissolving of Pr<sub>6</sub>O<sub>11</sub> in the LiF-PrF<sub>3</sub> melt, the predominant anionic species formed are [PrOF<sub>6</sub>]<sup>5-</sup>, [Pr<sub>2</sub>OF<sub>5</sub>]<sup>-</sup>, [Pr<sub>2</sub>OF<sub>8</sub>]<sup>4-</sup>, [Pr<sub>2</sub>OF<sub>9</sub>]<sup>5-</sup> and [Pr<sub>2</sub>OF<sub>10</sub>]<sup>6-</sup>. An increase in CR promotes the transformation of [Pr<sub>2</sub>OF<sub>x</sub>]<sup>4−x</sup> anions into structures with higher fluoride coordination numbers. Simultaneously, the content of [PrOF<sub>6</sub>]<sup>5-</sup> anions increases progressively, and when the CR exceeds 3, [PrOF<sub>6</sub>]<sup>5-</sup> becomes the dominant anionic species in the melt. Increasing the melt temperature inhibits the coordination reactions of [Pr<sub>2</sub>OF<sub>x</sub>]<sup>4−x</sup> anions and accelerates their dissociation into [PrOF<sub>x</sub>]<sup>1−x</sup> anions.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102863"},"PeriodicalIF":1.9,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144738206","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 : 2025-07-28DOI: 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":"2025-07-28","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 : 2025-07-25DOI: 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":"2025-07-25","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}
Pub Date : 2025-07-23DOI: 10.1016/j.calphad.2025.102849
Bo Sundman , Fabio Miani , Axel van de Walle , Bengt Hallstedt , Ursula R. Kattner , Florian Tang , Taichi Abe , Reza Naraghi , Erwin Povoden-Karadeniz , Aurelie Jacob , Shuanglin Chen , Richard Otis , Kazuhisa Shobu , Malin Selleby , Alexander Pisch
The calculation of phase diagram (Calphad) method uses models that depend on assessed parameters to describe the thermodynamic properties of materials. These model parameters are assessed by researchers and students using experimental and theoretical data on binary and ternary systems that can be merged to multicomponent databases and used to calculate properties and simulate processes for a wide range of materials.
There are several different software using the Calphad method for calculations and they may use slightly different models and database formats. This paper will provide a short background on the current state of database development and proposes a new format based on the eXtensive Markup Language (XML) as a unified database format. This change is particularly important as several new models for the pure elements are currently being introduced in the Calphad databases.
{"title":"XTDB, an XML based format for Calphad databases","authors":"Bo Sundman , Fabio Miani , Axel van de Walle , Bengt Hallstedt , Ursula R. Kattner , Florian Tang , Taichi Abe , Reza Naraghi , Erwin Povoden-Karadeniz , Aurelie Jacob , Shuanglin Chen , Richard Otis , Kazuhisa Shobu , Malin Selleby , Alexander Pisch","doi":"10.1016/j.calphad.2025.102849","DOIUrl":"10.1016/j.calphad.2025.102849","url":null,"abstract":"<div><div>The calculation of phase diagram (Calphad) method uses models that depend on assessed parameters to describe the thermodynamic properties of materials. These model parameters are assessed by researchers and students using experimental and theoretical data on binary and ternary systems that can be merged to multicomponent databases and used to calculate properties and simulate processes for a wide range of materials.</div><div>There are several different software using the Calphad method for calculations and they may use slightly different models and database formats. This paper will provide a short background on the current state of database development and proposes a new format based on the eXtensive Markup Language (XML) as a unified database format. This change is particularly important as several new models for the pure elements are currently being introduced in the Calphad databases.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102849"},"PeriodicalIF":1.9,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144687100","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 : 2025-07-22DOI: 10.1016/j.calphad.2025.102859
M. Li, M.H. Rong, Y. Wu, P.F. Tan, J. Wang
The phase equilibria and thermodynamic properties of Au-Sn-based alloys are of great significance for designing Au-based alloys as lead-free solders to replace high-lead solders. In this work, based on the experimental data reported in the literature, thermodynamic parameters of AuSn2 and AuSn4 in the Au-Sn binary system were modified. The calculated phase diagram and thermodynamic properties of the Au-Sn binary system are in good agreement with the experimental results. Furthermore, by combining the updated calculations of the Au-Sn binary system in this work with the previous assessments of the Au-Bi, Au-Zn, Au-Ni, Sn-Bi, Sn-Zn and Sn-Ni binary systems, thermodynamic modeling of the Au-Sn-X (X = Bi, Zn, Ni) ternary systems was conducted using the CALPHAD method. The liquidus projections, isothermal sections and vertical sections of the Au-Sn-X (X = Bi, Zn, Ni) ternary systems were calculated, which are in good agreement with the reported experimental data. The reasonable thermodynamic parameters of the Au-Sn-X (X = Bi, Zn, Ni) ternary systems were obtained in this work, which would provide a good foundation for further establishing a compatible thermodynamic database of multi-component Au-Sn-based alloy systems to design novel lead-free solders.
{"title":"Thermodynamic modeling of the Au-Sn-X (X=Bi, Zn, Ni) ternary systems","authors":"M. Li, M.H. Rong, Y. Wu, P.F. Tan, J. Wang","doi":"10.1016/j.calphad.2025.102859","DOIUrl":"10.1016/j.calphad.2025.102859","url":null,"abstract":"<div><div>The phase equilibria and thermodynamic properties of Au-Sn-based alloys are of great significance for designing Au-based alloys as lead-free solders to replace high-lead solders. In this work, based on the experimental data reported in the literature, thermodynamic parameters of AuSn<sub>2</sub> and AuSn<sub>4</sub> in the Au-Sn binary system were modified. The calculated phase diagram and thermodynamic properties of the Au-Sn binary system are in good agreement with the experimental results. Furthermore, by combining the updated calculations of the Au-Sn binary system in this work with the previous assessments of the Au-Bi, Au-Zn, Au-Ni, Sn-Bi, Sn-Zn and Sn-Ni binary systems, thermodynamic modeling of the Au-Sn-X (X = Bi, Zn, Ni) ternary systems was conducted using the CALPHAD method. The liquidus projections, isothermal sections and vertical sections of the Au-Sn-X (X = Bi, Zn, Ni) ternary systems were calculated, which are in good agreement with the reported experimental data. The reasonable thermodynamic parameters of the Au-Sn-X (X = Bi, Zn, Ni) ternary systems were obtained in this work, which would provide a good foundation for further establishing a compatible thermodynamic database of multi-component Au-Sn-based alloy systems to design novel lead-free solders.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102859"},"PeriodicalIF":1.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680185","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 : 2025-07-21DOI: 10.1016/j.calphad.2025.102857
Xinming Wang , Jia Liu , Jingxian Hu , Weimin Bai , Ying Ran , Fucheng Yin , Lebin Zhao , Jinhui Tang
Ni-based superalloys have excellent high-temperature strength, oxidation resistance and creep resistance. Mo, Fe and W are important γ phase stable elements in nickel-based superalloys. The diffusion behavior of alloying elements in fcc phase Ni-Fe-X (X = Mo, W) alloys plays an important role in the microstructure evolution and material fabrication of Ni-based superalloys. In this work, the diffusion coefficients of the fcc Ni-Fe-X (X = Mo, W) system were determined by using the diffusion couple technique and the Whittle-Green method, and the atomic mobilities were evaluated based on the CALPHAD technique with the DICTRA module of the Thermo-calc software. Based on the evaluated mobility parameters, the calculation of diffusion coefficients and simulation of the diffusion processes of the diffusion couples were carried out to verify the accuracy of the parameters. The calculated diffusion coefficients and predicted composition-distance profiles and diffusion paths show good agreement with the experimental results.
{"title":"Diffusivities and atomic mobilities in the fcc phase Ni-Fe-X (X=Mo, W) system","authors":"Xinming Wang , Jia Liu , Jingxian Hu , Weimin Bai , Ying Ran , Fucheng Yin , Lebin Zhao , Jinhui Tang","doi":"10.1016/j.calphad.2025.102857","DOIUrl":"10.1016/j.calphad.2025.102857","url":null,"abstract":"<div><div>Ni-based superalloys have excellent high-temperature strength, oxidation resistance and creep resistance. Mo, Fe and W are important γ phase stable elements in nickel-based superalloys. The diffusion behavior of alloying elements in fcc phase Ni-Fe-X (X = Mo, W) alloys plays an important role in the microstructure evolution and material fabrication of Ni-based superalloys. In this work, the diffusion coefficients of the fcc Ni-Fe-X (X = Mo, W) system were determined by using the diffusion couple technique and the Whittle-Green method, and the atomic mobilities were evaluated based on the CALPHAD technique with the DICTRA module of the Thermo-calc software. Based on the evaluated mobility parameters, the calculation of diffusion coefficients and simulation of the diffusion processes of the diffusion couples were carried out to verify the accuracy of the parameters. The calculated diffusion coefficients and predicted composition-distance profiles and diffusion paths show good agreement with the experimental results.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"90 ","pages":"Article 102857"},"PeriodicalIF":1.9,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144672079","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":"2025-07-18","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}
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