Modelling of phase equilibria in the Hf-V system below room temperature
Phase transformation from orthorhombic HfV2 structure to cubic C15 Laves phase structure, which occurs during heating at about 114 K, is well known. In this contribution, a thermodynamic description of this phenomenon is provided supported by ab initio calculations. We utilize the third gen...
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University of Belgrade, Technical Faculty, Bor
2017-01-01
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| Series: | Journal of Mining and Metallurgy. Section B: Metallurgy |
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| Online Access: | http://www.doiserbia.nb.rs/img/doi/1450-5339/2017/1450-53391700032V.pdf |
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| author | Vřešťál J. Pavlů J. Wdowik U.D. Šob M. |
| author_facet | Vřešťál J. Pavlů J. Wdowik U.D. Šob M. |
| author_sort | Vřešťál J. |
| collection | DOAJ |
| description | Phase transformation from orthorhombic HfV2 structure to cubic C15 Laves
phase structure, which occurs during heating at about 114 K, is well known.
In this contribution, a thermodynamic description of this phenomenon is
provided supported by ab initio calculations. We utilize the third generation
of thermodynamic database extending the Scientific Group Thermodata Europe
(SGTE) unary data to zero Kelvin and demonstrate that it may be also applied
to intermetallic phases. The data from a recent thermodynamic assessment of
the Hf-V system (valid for temperatures above 298.15 K) were used and
extended to zero Kelvin by the same method as it was used for unary data.
Under the assumption of validity of harmonic approximation and electronic
contribution to the heat capacity, the thermodynamics of C15 and orthorhombic
phase were described. With the help of ab initio approach, we demonstrate
that the HfV2 orthorhombic phase and C15 Laves phase are mechanically stable
at 0 K and thanks to entropy stabilization they are in equilibrium with pure
element phases in the temperature region of structural change. |
| format | Article |
| id | doaj-art-533ea04567124abdb87d1d1521ac08a1 |
| institution | Kabale University |
| issn | 1450-5339 2217-7175 |
| language | English |
| publishDate | 2017-01-01 |
| publisher | University of Belgrade, Technical Faculty, Bor |
| record_format | Article |
| series | Journal of Mining and Metallurgy. Section B: Metallurgy |
| spelling | doaj-art-533ea04567124abdb87d1d1521ac08a12025-02-02T18:04:22ZengUniversity of Belgrade, Technical Faculty, BorJournal of Mining and Metallurgy. Section B: Metallurgy1450-53392217-71752017-01-0153323924710.2298/JMMB170704032V1450-53391700032VModelling of phase equilibria in the Hf-V system below room temperatureVřešťál J.0Pavlů J.1Wdowik U.D.2Šob M.3Masaryk University, Central European Institute of Technology, CEITEC MU, Brno, Czech Republic + Academy of Sciences of the Czech Republic, Institute of Physics of Materials, Brno, Czech Republic + Masaryk University, Faculty of Science, Department of ChemMasaryk University, Central European Institute of Technology, CEITEC MU, Brno, Czech Republic + Academy of Sciences of the Czech Republic, Institute of Physics of Materials, Brno, Czech Republic + Masaryk University, Faculty of Science, Department of ChemPedagogical University, Institute of Technology, Cracow, PolandMasaryk University, Central European Institute of Technology, CEITEC MU, Brno, Czech Republic + Academy of Sciences of the Czech Republic, Institute of Physics of Materials, Brno, Czech Republic + Masaryk University, Faculty of Science, Department of ChemPhase transformation from orthorhombic HfV2 structure to cubic C15 Laves phase structure, which occurs during heating at about 114 K, is well known. In this contribution, a thermodynamic description of this phenomenon is provided supported by ab initio calculations. We utilize the third generation of thermodynamic database extending the Scientific Group Thermodata Europe (SGTE) unary data to zero Kelvin and demonstrate that it may be also applied to intermetallic phases. The data from a recent thermodynamic assessment of the Hf-V system (valid for temperatures above 298.15 K) were used and extended to zero Kelvin by the same method as it was used for unary data. Under the assumption of validity of harmonic approximation and electronic contribution to the heat capacity, the thermodynamics of C15 and orthorhombic phase were described. With the help of ab initio approach, we demonstrate that the HfV2 orthorhombic phase and C15 Laves phase are mechanically stable at 0 K and thanks to entropy stabilization they are in equilibrium with pure element phases in the temperature region of structural change.http://www.doiserbia.nb.rs/img/doi/1450-5339/2017/1450-53391700032V.pdfLaves phasesHf-V systemAb initio calculationsPhase diagramZero KelvinCALPHAD method |
| spellingShingle | Vřešťál J. Pavlů J. Wdowik U.D. Šob M. Modelling of phase equilibria in the Hf-V system below room temperature Journal of Mining and Metallurgy. Section B: Metallurgy Laves phases Hf-V system Ab initio calculations Phase diagram Zero Kelvin CALPHAD method |
| title | Modelling of phase equilibria in the Hf-V system below room temperature |
| title_full | Modelling of phase equilibria in the Hf-V system below room temperature |
| title_fullStr | Modelling of phase equilibria in the Hf-V system below room temperature |
| title_full_unstemmed | Modelling of phase equilibria in the Hf-V system below room temperature |
| title_short | Modelling of phase equilibria in the Hf-V system below room temperature |
| title_sort | modelling of phase equilibria in the hf v system below room temperature |
| topic | Laves phases Hf-V system Ab initio calculations Phase diagram Zero Kelvin CALPHAD method |
| url | http://www.doiserbia.nb.rs/img/doi/1450-5339/2017/1450-53391700032V.pdf |
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