High-temperature phenomena in an advanced intermetallic nano-lamellar γ-TiAl-based alloy. Part I: Internal friction and atomic relaxation processes
Intermetallic γ-TiAl based alloys have found applications in the low-pressure turbine of aircraft engines as well as in the turbocharger unit of automotive engines. However, these light-weight alloys must still be improved, through micro-alloying and tailoring the microstructure, to increase their c...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Universidad del País Vasco |
| Repositorio: | Addi. Archivo Digital para la Docencia y la Investigación |
| OAI Identifier: | oai:addi.ehu.eus:10810/72002 |
| Acceso en línea: | http://hdl.handle.net/10810/72002 |
| Access Level: | acceso abierto |
| Palabra clave: | intermetallics Titanium aluminides internal friction atomic mobility diffusion mechanism |
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High-temperature phenomena in an advanced intermetallic nano-lamellar γ-TiAl-based alloy. Part I: Internal friction and atomic relaxation processesUsategui Frías, LeireKlein, ThomasNó Sánchez, María LuisaMayer, SveaClemens, HelmutSan Juan Núñez, José MaríaintermetallicsTitanium aluminidesinternal frictionatomic mobilitydiffusion mechanismIntermetallic γ-TiAl based alloys have found applications in the low-pressure turbine of aircraft engines as well as in the turbocharger unit of automotive engines. However, these light-weight alloys must still be improved, through micro-alloying and tailoring the microstructure, to increase their creep resistance and consequently their maximum working temperature. In this work, a fully nano-lamellar advanced γ-TiAl based alloy doped with small amounts of C and Si is investigated in order to gain a deeper understanding of the atomic mobility mechanisms taking place at high temperature, thus controlling the creep properties. The study was approached through internal friction measurements up to 1223 K. We demonstrate that C has a notable influence on Ti diffusion in α2 phase, leading to an increase of the activation energy for Ti diffusion, which is assessed at ΔETi(α2)=0.32 eV per at% C. An atomic model for the relaxation process is proposed capable to explain this phenomenon. An additional internal friction peak, which, up to now, remained hidden by the high temperature background, was observed in this nano-lamellar TiAl alloy and analyzed through a careful de-convolution of the internal friction spectra. This new relaxation process, with activation energy of 3.70 eV, is attributed to the short distance diffusion of Al atoms in the γ-TiAl lattice. A novel concept of stress-induced cell-lattice reorientation is proposed to explain this relaxation. Finally, a new experimental method to analyze the high temperature internal friction background, which is closely related to the creep behavior, was developed to study the fully nano-lamellar microstructure, whose high temperature background exhibits the highest activation energy ever measured in a γ-TiAl based alloy.This work was supported by the Spanish MINECO through the project CONSOLIDER-INGENIO 2010 CSD2009-00013 and further Network, as well as by the Consolidated Research Group GIU-17/071 from the University of the Basque Country, UPV/EHU, and the project ETORTEK ACTIMAT from the Industry Department of the Basque Government. This work made use of the FEI-TITAN of the SGIKER from the UPV/EHU.Elsevier202520252020info:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10810/72002reponame:Addi. Archivo Digital para la Docencia y la Investigacióninstname:Universidad del País VascoIngléshttps://www.sciencedirect.com/science/article/pii/S1359645420307199info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-nd/4.0/© 2020 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND 4.0 licenseoai:addi.ehu.eus:10810/720022026-06-18T09:23:17Z |
| dc.title.none.fl_str_mv |
High-temperature phenomena in an advanced intermetallic nano-lamellar γ-TiAl-based alloy. Part I: Internal friction and atomic relaxation processes |
| title |
High-temperature phenomena in an advanced intermetallic nano-lamellar γ-TiAl-based alloy. Part I: Internal friction and atomic relaxation processes |
| spellingShingle |
High-temperature phenomena in an advanced intermetallic nano-lamellar γ-TiAl-based alloy. Part I: Internal friction and atomic relaxation processes Usategui Frías, Leire intermetallics Titanium aluminides internal friction atomic mobility diffusion mechanism |
| title_short |
High-temperature phenomena in an advanced intermetallic nano-lamellar γ-TiAl-based alloy. Part I: Internal friction and atomic relaxation processes |
| title_full |
High-temperature phenomena in an advanced intermetallic nano-lamellar γ-TiAl-based alloy. Part I: Internal friction and atomic relaxation processes |
| title_fullStr |
High-temperature phenomena in an advanced intermetallic nano-lamellar γ-TiAl-based alloy. Part I: Internal friction and atomic relaxation processes |
| title_full_unstemmed |
High-temperature phenomena in an advanced intermetallic nano-lamellar γ-TiAl-based alloy. Part I: Internal friction and atomic relaxation processes |
| title_sort |
High-temperature phenomena in an advanced intermetallic nano-lamellar γ-TiAl-based alloy. Part I: Internal friction and atomic relaxation processes |
| dc.creator.none.fl_str_mv |
Usategui Frías, Leire Klein, Thomas Nó Sánchez, María Luisa Mayer, Svea Clemens, Helmut San Juan Núñez, José María |
| author |
Usategui Frías, Leire |
| author_facet |
Usategui Frías, Leire Klein, Thomas Nó Sánchez, María Luisa Mayer, Svea Clemens, Helmut San Juan Núñez, José María |
| author_role |
author |
| author2 |
Klein, Thomas Nó Sánchez, María Luisa Mayer, Svea Clemens, Helmut San Juan Núñez, José María |
| author2_role |
author author author author author |
| dc.subject.none.fl_str_mv |
intermetallics Titanium aluminides internal friction atomic mobility diffusion mechanism |
| topic |
intermetallics Titanium aluminides internal friction atomic mobility diffusion mechanism |
| description |
Intermetallic γ-TiAl based alloys have found applications in the low-pressure turbine of aircraft engines as well as in the turbocharger unit of automotive engines. However, these light-weight alloys must still be improved, through micro-alloying and tailoring the microstructure, to increase their creep resistance and consequently their maximum working temperature. In this work, a fully nano-lamellar advanced γ-TiAl based alloy doped with small amounts of C and Si is investigated in order to gain a deeper understanding of the atomic mobility mechanisms taking place at high temperature, thus controlling the creep properties. The study was approached through internal friction measurements up to 1223 K. We demonstrate that C has a notable influence on Ti diffusion in α2 phase, leading to an increase of the activation energy for Ti diffusion, which is assessed at ΔETi(α2)=0.32 eV per at% C. An atomic model for the relaxation process is proposed capable to explain this phenomenon. An additional internal friction peak, which, up to now, remained hidden by the high temperature background, was observed in this nano-lamellar TiAl alloy and analyzed through a careful de-convolution of the internal friction spectra. This new relaxation process, with activation energy of 3.70 eV, is attributed to the short distance diffusion of Al atoms in the γ-TiAl lattice. A novel concept of stress-induced cell-lattice reorientation is proposed to explain this relaxation. Finally, a new experimental method to analyze the high temperature internal friction background, which is closely related to the creep behavior, was developed to study the fully nano-lamellar microstructure, whose high temperature background exhibits the highest activation energy ever measured in a γ-TiAl based alloy. |
| publishDate |
2020 |
| dc.date.none.fl_str_mv |
2020 2025 2025 |
| dc.type.none.fl_str_mv |
info:eu-repo/semantics/article |
| format |
article |
| dc.identifier.none.fl_str_mv |
http://hdl.handle.net/10810/72002 |
| url |
http://hdl.handle.net/10810/72002 |
| dc.language.none.fl_str_mv |
Inglés |
| language_invalid_str_mv |
Inglés |
| dc.relation.none.fl_str_mv |
https://www.sciencedirect.com/science/article/pii/S1359645420307199 |
| dc.rights.none.fl_str_mv |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by-nc-nd/4.0/ |
| eu_rights_str_mv |
openAccess |
| rights_invalid_str_mv |
http://creativecommons.org/licenses/by-nc-nd/4.0/ |
| dc.format.none.fl_str_mv |
application/pdf |
| dc.publisher.none.fl_str_mv |
Elsevier |
| publisher.none.fl_str_mv |
Elsevier |
| dc.source.none.fl_str_mv |
reponame:Addi. Archivo Digital para la Docencia y la Investigación instname:Universidad del País Vasco |
| instname_str |
Universidad del País Vasco |
| reponame_str |
Addi. Archivo Digital para la Docencia y la Investigación |
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Addi. Archivo Digital para la Docencia y la Investigación |
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| repository.mail.fl_str_mv |
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1869422206148149248 |
| score |
15,812429 |