Thermal Stability of Microstructure of High-Entropy Alloys Based on Refractory Metals Hf, Nb, Ta, Ti, V, and Zr
In the present work, a series of high-entropy alloys based on refractory metals Hf, Nb, Ta, Ti, V, and Zr with various compositions have been systematically investigated. Our study revealed that a bcc single-phase solid solution of a Hf-Nb-Ta-Ti-V-Zr system is thermodynamically stable only at high t...
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MDPI AG
2022-02-01
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| Online Access: | https://www.mdpi.com/2075-4701/12/3/394 |
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| author | Tomáš Vlasák Jakub Čížek Oksana Melikhova František Lukáč Dalibor Preisler Miloš Janeček Petr Harcuba Mariia Zimina Ondřej Srba |
| author_facet | Tomáš Vlasák Jakub Čížek Oksana Melikhova František Lukáč Dalibor Preisler Miloš Janeček Petr Harcuba Mariia Zimina Ondřej Srba |
| author_sort | Tomáš Vlasák |
| collection | DOAJ |
| description | In the present work, a series of high-entropy alloys based on refractory metals Hf, Nb, Ta, Ti, V, and Zr with various compositions have been systematically investigated. Our study revealed that a bcc single-phase solid solution of a Hf-Nb-Ta-Ti-V-Zr system is thermodynamically stable only at high temperatures above 1000 °C. At lower temperatures, the phase separation into disordered bcc phases with slightly different chemical compositions occurs. Despite the phase separation, a single-phase random solid solution can be saved at room temperature as a metastable phase by rapid cooling of the sample from high temperature. The microstructure of a single-phase metastable random solid solution was characterized and compared with the microstructure of the as-cast state. Furthermore, the mechanical properties of annealed and as-cast alloys were compared. Interestingly, both states exhibit comparable mechanical properties. It indicates that from the point of view of practical applications, a mechanical mixture of disordered bcc solutions is as good as single-phase random solid solution. |
| first_indexed | 2024-03-09T13:20:13Z |
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| id | doaj.art-39e34062ebec40ea8b89554e62bf8f00 |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-09T13:20:13Z |
| publishDate | 2022-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-39e34062ebec40ea8b89554e62bf8f002023-11-30T21:30:33ZengMDPI AGMetals2075-47012022-02-0112339410.3390/met12030394Thermal Stability of Microstructure of High-Entropy Alloys Based on Refractory Metals Hf, Nb, Ta, Ti, V, and ZrTomáš Vlasák0Jakub Čížek1Oksana Melikhova2František Lukáč3Dalibor Preisler4Miloš Janeček5Petr Harcuba6Mariia Zimina7Ondřej Srba8Department of Low Temperature Physics, Charles University, V Holešovičkách 2, Prague 8, 180 00 Prague, Czech RepublicDepartment of Low Temperature Physics, Charles University, V Holešovičkách 2, Prague 8, 180 00 Prague, Czech RepublicDepartment of Low Temperature Physics, Charles University, V Holešovičkách 2, Prague 8, 180 00 Prague, Czech RepublicDepartment of Low Temperature Physics, Charles University, V Holešovičkách 2, Prague 8, 180 00 Prague, Czech RepublicDepartment of Physics of Materials, Charles University, Ke Karlovu 5, 121 16 Prague, Czech RepublicDepartment of Physics of Materials, Charles University, Ke Karlovu 5, 121 16 Prague, Czech RepublicDepartment of Physics of Materials, Charles University, Ke Karlovu 5, 121 16 Prague, Czech RepublicCentrum Výzkumu Řež s.r.o., Hlavní 130, 250 68 Husinec, Czech RepublicCentrum Výzkumu Řež s.r.o., Hlavní 130, 250 68 Husinec, Czech RepublicIn the present work, a series of high-entropy alloys based on refractory metals Hf, Nb, Ta, Ti, V, and Zr with various compositions have been systematically investigated. Our study revealed that a bcc single-phase solid solution of a Hf-Nb-Ta-Ti-V-Zr system is thermodynamically stable only at high temperatures above 1000 °C. At lower temperatures, the phase separation into disordered bcc phases with slightly different chemical compositions occurs. Despite the phase separation, a single-phase random solid solution can be saved at room temperature as a metastable phase by rapid cooling of the sample from high temperature. The microstructure of a single-phase metastable random solid solution was characterized and compared with the microstructure of the as-cast state. Furthermore, the mechanical properties of annealed and as-cast alloys were compared. Interestingly, both states exhibit comparable mechanical properties. It indicates that from the point of view of practical applications, a mechanical mixture of disordered bcc solutions is as good as single-phase random solid solution.https://www.mdpi.com/2075-4701/12/3/394high-entropy alloysrefractory metalssolid solution |
| spellingShingle | Tomáš Vlasák Jakub Čížek Oksana Melikhova František Lukáč Dalibor Preisler Miloš Janeček Petr Harcuba Mariia Zimina Ondřej Srba Thermal Stability of Microstructure of High-Entropy Alloys Based on Refractory Metals Hf, Nb, Ta, Ti, V, and Zr Metals high-entropy alloys refractory metals solid solution |
| title | Thermal Stability of Microstructure of High-Entropy Alloys Based on Refractory Metals Hf, Nb, Ta, Ti, V, and Zr |
| title_full | Thermal Stability of Microstructure of High-Entropy Alloys Based on Refractory Metals Hf, Nb, Ta, Ti, V, and Zr |
| title_fullStr | Thermal Stability of Microstructure of High-Entropy Alloys Based on Refractory Metals Hf, Nb, Ta, Ti, V, and Zr |
| title_full_unstemmed | Thermal Stability of Microstructure of High-Entropy Alloys Based on Refractory Metals Hf, Nb, Ta, Ti, V, and Zr |
| title_short | Thermal Stability of Microstructure of High-Entropy Alloys Based on Refractory Metals Hf, Nb, Ta, Ti, V, and Zr |
| title_sort | thermal stability of microstructure of high entropy alloys based on refractory metals hf nb ta ti v and zr |
| topic | high-entropy alloys refractory metals solid solution |
| url | https://www.mdpi.com/2075-4701/12/3/394 |
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