Calphad-computer Coupling of Phase Diagrams and Thermochemistry最新文献

{"title":"Thermodynamic assessment of the Cr–Si binary system","authors":"Kazushige Ioroi ,&nbsp;Ikuo Ohnuma ,&nbsp;Xiao Xu ,&nbsp;Ryosuke Kainuma ,&nbsp;Toshihiro Omori","doi":"10.1016/j.calphad.2024.102690","DOIUrl":"https://doi.org/10.1016/j.calphad.2024.102690","url":null,"abstract":"<div><p>A thermodynamic evaluation of the Cr–Si system was performed concerning the latest experimental phase diagram and with the aid of first-principles calculations. The thermodynamic parameters for the Gibbs energy of pure Cr were modified based on the new experimental value of 1861 °C for the melting point of pure Cr, which was previously reported as 1907 °C in the SGTE database. The Gibbs energy descriptions of the Cr₃Si and Cr₅Si₃ phases were revised using Cr₃(Cr,Si)- and (Cr,Si)₅Si₃-type two-sublattice models to reproduce the latest experimental results of their solubility composition ranges, that is, Cr₃Si extending toward the Cr-rich side and Cr₅Si₃ extending toward the Si-rich side from the stoichiometry. The CrSi and CrSi₂ phases were considered line compounds with no solubility range, and the solubility of Cr in the Si phase was ignored. A set of self-consistent thermodynamic parameters for the Cr–Si system was obtained using the CALPHAD technique. The phase diagrams calculated using the optimized parameters showed reasonable agreement with the latest phase equilibrium data and thermodynamic property data in the literature, including the enthalpy of mixing, formation enthalpy, and chemical potential diagrams of Cr and Si in the equilibrium phases.</p></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140533427","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}

{"title":"Optimizing the heat capacities of sphalerite phases as single system, or how nuclear physics can help physical chemistry","authors":"V.P. Vassiliev ,&nbsp;A.S. Leonov ,&nbsp;S.A. Kulinich","doi":"10.1016/j.calphad.2024.102687","DOIUrl":"https://doi.org/10.1016/j.calphad.2024.102687","url":null,"abstract":"<div><p>The correct mathematical description of heat capacities <em>C</em>_p in a wide range of temperatures is still unsolved problem. A fragmental description of some phases is like a vision of one part of a large mosaic picture. A single description of <em>C</em>_p or other property of a phase of any isostructural series does not allow one to see the integrity of the entire ensemble. We propose a special mathematical model to describe <em>C</em>_p in a wide temperature range for a whole large class of isostructural sphalerite phases. In the proposed model, it is believed that an ideal crystal does not have any foreign inclusions, defects, or dislocations. The group IV elements (Si, Ge, α-Sn and diamond-like Pb) were taken as the basis, with flerovium (¹¹⁴Fl) closing this group. There should be no other elements in this group according to the fine structure constant (<em>α</em>) (or the Sommerfeld constant). As a consequence, the limiting value of the heat capacities of phases with a sphalerite structure falls on the element 114 (¹¹⁴Fl) and has a value of <em>C</em>_p = 30.5 ± 0.3 J · mol-at⁻¹ · K⁻¹. This value was obtained as a maximal virtual point <em>C</em>_p of the last element (¹¹⁴Fl) of group IV and corresponds to Ln (<em>C</em>_p/<em>R</em>) = 1.30 ± 0.01 for the isotherms ln (<em>C</em>_p/<em>R</em>) vs Ln(<em>N</em>), where <em>N</em> is an atomic number of an element of group IV or the sum of the atomic numbers of A^IIIB^V or A^IIB^VI compounds per mole-atom. The common point of heat capacity attributable to flerovium is obtained from the linear equations <em>С</em>_р/<em>R</em> vs Ln(<em>N</em>) at low temperatures from 25 to 35K. For only pure elements of group IV (Si, Ge, α-Sn and diamond-like Pb), flerovium closes this group, and there are no other elements behind it, according to <em>α</em>. The maximum heat capacity of flerovium can be taken as 30.5 J·mol-at⁻¹·K⁻¹ with an accuracy of 1%. As the temperature decreases, this value slowly decreases (within 1%), and then, when it approaches 0 K, it drops sharply to 0 J·mol-at⁻¹·K⁻¹. To describe the set of the isostructural experimental data <em>C</em>_p(<em>T</em>) for diamond-like phases in solid state as a whole system, here we used a special multi-parameter family of functions. For each substance, the parameters are found by minimizing the discrepancy between the theoretical dependence <em>C</em>_p(<em>T</em>) and corresponding experimental data. The dependence of the heat capacities for elements of group IV (Si, Ge, α-Sn, diamond-like Pb, Fl) at fixed temperatures on Ln(<em>N</em>), where <em>N</em> is the atomic number or the demi sum of the atomic numbers of phases A^IIB^VI or A^IIIB^V. In this case, ei","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140344487","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}

{"title":"Thermodynamic reassessment of Sn–Zr system assisted by DFT phonon calculations","authors":"Jiaqing Peng ,&nbsp;Jianyun Shen ,&nbsp;Xuankai Feng ,&nbsp;Zhuqing Cheng","doi":"10.1016/j.calphad.2024.102672","DOIUrl":"https://doi.org/10.1016/j.calphad.2024.102672","url":null,"abstract":"<div><p>The Sn–Zr system was re-assessed thermodynamically. Gibbs free energies of the intermetallic compounds of this system were calculated by DFT phonon calculations which can give more reliable information owing to considering the contributions of lattice vibration and electric thermal excitation. Newly published valuable experimental data of liquidus, solidus and invariant reactions of this system were used for the first time in the optimization of the model parameters. It is shown that the previous thermodynamic models, where the Gibbs free energies of formation at different temperatures were replaced by energies of formation at 0 K, overestimated obviously the stability of all the compounds of this system. The thermodynamic model for the Sn–Zr system established in this work would give more solid prediction of phase structures and thermodynamic properties for materials containing Sn–Zr system.</p></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140139120","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}

{"title":"Phase diagram of ternary Co–Fe–Ge system (I): Experimental","authors":"Yao-de Guo ,&nbsp;Yohanes Hutabalian ,&nbsp;Sinn-wen Chen","doi":"10.1016/j.calphad.2024.102682","DOIUrl":"https://doi.org/10.1016/j.calphad.2024.102682","url":null,"abstract":"<div><p>Co–Fe–Ge is an important material system for magnetic and catalyst applications. However, phase equilibria information of the Co–Fe–Ge ternary system is limited. Ternary Co–Fe–Ge alloys equilibrated at 950 °C were prepared. The microstructures, chemical compositions and crystal structure of each phase were determined. The phase equilibria isothermal section at 950 °C of the Co–Fe–Ge ternary system was then proposed. A continuous solid solution phase was formed between the Co₅Ge₃ and Fe₅Ge₃ phases and was labeled the β(Co,Fe)₅Ge₃ phase. There are five three-phase regions in the system at 950 °C. A wide α₂ single-phase, and liquid phase regions with large composition ranges being confirmed at the Ge-poor and Ge-rich sides, respectively.</p></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140139119","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}

{"title":"Experimental investigation and thermodynamic modeling of the Al–Dy and Ni–Al−Dy systems","authors":"Dupei Ma ,&nbsp;Yi ting Guo ,&nbsp;Zhi Li ,&nbsp;Jingxian Hu ,&nbsp;Fucheng Yin ,&nbsp;Yan Liu ,&nbsp;Ye Liu","doi":"10.1016/j.calphad.2024.102681","DOIUrl":"https://doi.org/10.1016/j.calphad.2024.102681","url":null,"abstract":"<div><p>The partial phase equilibria of the Ni–Al−Dy ternary system have been systematically investigated via experimental analyses and thermodynamic modeling. Using the equilibrated alloy method, the 1150 °C and partial 800 °C isothermal sections of the Ni–Al−Dy ternary system and related Al–Dy binary system were constructed based on scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction. Twelve three-phase regions were confirmed and four three-phase equilibria regions were speculated at 1150 °C, eight three-phase regions were determined at 800 °C, and five kinds of primary solidification regions, DyAl₂, τ7, τ5, NiAl and Ni₂Al₃ were observed. A new ternary compound τ12 was discovered, which was stable at 800 °C and disappeared at 1150 °C, the τ1 phase was not stable at 800 and 1150 °C isothermal sections; the ternary compound τ11 was confirmed to be stable at 800 °C. In addition, the primary solidification phases were also identified, and five different primary solidification phases were found. Based on the experimental results available in this study and the literature, the thermodynamic modeling of the Ni–Al–Dy ternary system was obtained using the CALPHAD method. A set of self-consistent thermodynamic parameters for the Ni–Al–Dy ternary system was first obtained with a satisfactory agreement between the experimental and calculated results.</p></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140133821","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}

{"title":"The isothermal section of the phase diagram of Gd-Mn-Ga (≤50 at.%Ga) ternary system at 873K","authors":"Qian Wang ,&nbsp;Wei He ,&nbsp;Tonghan Yang ,&nbsp;Yifei Bi ,&nbsp;Yunxiang Yang ,&nbsp;Chongjiang Li ,&nbsp;Changzhong Liao","doi":"10.1016/j.calphad.2024.102668","DOIUrl":"https://doi.org/10.1016/j.calphad.2024.102668","url":null,"abstract":"<div><p>The phase diagram of the Gd-Mn-Ga ternary system is a very important tool for the exploration and development of rare earth Heusler alloys with excellent physical properties, such as magnetic properties, half-metallic properties, ferromagnetic shape memory effect, magnetocaloric effect, ect. In this study, the alloy samples were prepared using a vacuum arc melting furnace, and the 873 K isothermal section of the Gd-Mn-Ga (≤50 at.%Ga) ternary alloy phase diagram was determined by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy spectrometry (EDS). The isothermal section consists of 22 single-phase regions, 44 two-phase regions, and 23 three-phase regions with the presence of 6 ternary compounds, GdMnGa, Gd₂MnGa₆, Gd₂Mn₁₅Ga₂, Gd₂Mn₁₁Ga₆, GdMn_0.56Ga_1.44, and GdMn_0.37Ga_1.63. The solid solubility ranges of Ga in β-Mn and Gd₂Mn₁₅Ga₂ are 5.0–18.1 at.%Ga and 10.5–25.0 at.% Ga. The maximum solid solubility of Ga in α-Mn, GdMn₁₂, and Gd₆Mn₂₃ are 2.0, 2.7, and 7.3 at.% Ga, respectively. The maximum solid solubility of Mn in GdGa₂ is determined to be 13.1 at.% Mn.</p></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140122412","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}

{"title":"Thermodynamic modeling of the Ti–Al–V system over the entire composition and a wide temperature range","authors":"Kuizhang Li ,&nbsp;Guodong Fan ,&nbsp;Weisen Zheng ,&nbsp;Jingya Wang","doi":"10.1016/j.calphad.2024.102683","DOIUrl":"https://doi.org/10.1016/j.calphad.2024.102683","url":null,"abstract":"<div><p>Ti–Al–V alloys have received considerable attention owing to their excellent high-temperature mechanical properties. After conducting a critical review of the available experimental data for the ternary Ti–Al–V system, a thermodynamic assessment of the system was carried out over the entire composition and a wide temperature range utilizing the CALPHAD method. The extensive homogeneity ranges of the <span><math><mrow><msub><mi>α</mi><mn>2</mn></msub></mrow></math></span> and <span><math><mrow><mi>γ</mi></mrow></math></span> phases were satisfactorily reproduced. Of particular significance was the first accurate description of the phase equilibria at 1573 K. The model parameters obtained in this study well represented the thermochemical properties and phase equilibria of the experimental data. Furthermore, the enthalpies of the widely used Ti alloy Ti–6Al–4V were reproduced using the thermodynamic description established in this study. Thus, this study provides a reliable basis for guiding the development and design of Ti–Al–V alloys.</p></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140113271","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}

{"title":"Metallurgical performance of Ca3TiFe2O8","authors":"Yongda Li ,&nbsp;Gang Li ,&nbsp;Ningyu Zhang ,&nbsp;Guishang Pei ,&nbsp;Yuxiao Xue ,&nbsp;Xuewei Lv","doi":"10.1016/j.calphad.2024.102671","DOIUrl":"https://doi.org/10.1016/j.calphad.2024.102671","url":null,"abstract":"<div><p>Ca₃TiFe₂O₈ (abbreviated as CTF), which is a significant mineral phase in the sinter of titanium-containing iron ore, was successfully prepared by solid-state reaction (calcined at 1553 K for 24 h) by using analytical reagents in this study. The metallurgical performance (melting performance and reduction behavior) was systemically characterized and the enthalpy change data of CTF was tested. The results show that softening temperature, melting temperature, and flowing temperature of CTF were 1691 K, 1734 K, and 1753 K, respectively. The non-isothermal reduction results revealed that CTF was reduced to Fe, CaO, and perovskite in a single step, and the CTF reduction was completed when the temperature reached 1423 K. The results of isothermal reduction shows that the reduction degree of CTF was 89% when reduced at 1173 K for 79.2 min, and the order of reduction performance was Fe₂O₃ &gt; Fe₃O₄ &gt; CaO∙2Fe₂O₃ &gt; CaO∙Fe₂O₃&gt; Ca₃TiFe₂O₈&gt; 2CaO∙Fe₂O₃&gt; Ca₃Fe₂Si_1.58Ti_1.42O₁₂.</p></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140103539","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}

{"title":"The effect of carbon vacancy on the properties of ZrC by MEAM potentials","authors":"Yifang Ouyang ,&nbsp;Meiling Xiong ,&nbsp;Kuixin Lin ,&nbsp;Yulu Zhou ,&nbsp;Hongmei Chen ,&nbsp;Xiaoma Tao ,&nbsp;Qing Peng ,&nbsp;Yong Du","doi":"10.1016/j.calphad.2024.102680","DOIUrl":"https://doi.org/10.1016/j.calphad.2024.102680","url":null,"abstract":"<div><p>A novel second-nearest-neighbor (2NN) modified embedded atom method (MEAM) potential for Zr–C system has been developed. The lattice constants, formation enthalpy, mechanical properties of stoichiometric ZrC have been reproduced. The melting point from the new 2NN-MEAM potential is 3436 K, which is coincident with the experimental melting point, ∼3530 K. The properties of sub-stoichiometric ZrC_<em>x</em> with ordered or disordered carbon vacancy have also been examined with the new potential. The results for ordered sub-stoichiometric ZrC_<em>x</em> agree well with the experimental data and/or first-principles calculations. The lattice parameter, elastic properties, thermodynamic properties change with the C/Zr ratio have been studied. The predicted relationships between the properties versus C/Zr ratio coincide with available experimental results. These results indicate the present 2NN-MEAM potential is suitable for atomic scale simulation of ZrC.</p></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140062070","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}

{"title":"Thermodynamic assessment of the Ta–Ge system supported by ab initio calculations","authors":"Antonio Augusto Araujo Pinto da Silva ,&nbsp;Pedro Pires Ferreira ,&nbsp;Thiago Trevizam Dorini ,&nbsp;Gilberto Carvalho Coelho ,&nbsp;Carlos Angelo Nunes ,&nbsp;Luiz Tadeu Fernandes Eleno","doi":"10.1016/j.calphad.2024.102669","DOIUrl":"https://doi.org/10.1016/j.calphad.2024.102669","url":null,"abstract":"<div><p>The Ta–Ge system was thermodynamically modeled for the first time using the CALPHAD method incorporating both literature-derived phase equilibria data and new enthalpy of formation values for the intermetallic compounds. Density Functional Theory (DFT) calculations were employed to accurately determine enthalpy of formation values for key Ta–Ge compounds. The stable intermetallic phases (i.e., αTa₃Ge, βTa₃Ge, βTa₅Ge₃, and TaGe₂) were described as stoichiometric phases while the Liquid (L), Ta-rich solid solution (BCC-A2), and Ge-rich solid solution (Diamond-A4) were modeled as solution phases using the Compound Energy Formalism. Excess terms were described by the Redlich-Kister polynomials. The present thermodynamic model accurately describes phase equilibria and thermodynamic data, providing a reliable guide for designing alloys containing Ta and Ge.</p></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139992707","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}