Comparative Study of Microstructure and Mechanical Properties of Two TiAl-Based Alloys Reinforced with Carbide Particles
Microstructure and mechanical properties of two TiAl-based alloys with nominal composition Ti-42.6Al-8.7Nb-0.3Ta-2.0C and Ti-41.0Al-8.7Nb-0.3Ta-3.6C (in at.%) were investigated and compared. The alloys were prepared by vacuum induction melting, followed by centrifugal casting. The as-cast samples we...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-07-01
|
| Series: | Molecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1420-3049/25/15/3423 |
| _version_ | 1827712168660828160 |
|---|---|
| author | Juraj Lapin Kateryna Kamyshnykova Alena Klimova |
| author_facet | Juraj Lapin Kateryna Kamyshnykova Alena Klimova |
| author_sort | Juraj Lapin |
| collection | DOAJ |
| description | Microstructure and mechanical properties of two TiAl-based alloys with nominal composition Ti-42.6Al-8.7Nb-0.3Ta-2.0C and Ti-41.0Al-8.7Nb-0.3Ta-3.6C (in at.%) were investigated and compared. The alloys were prepared by vacuum induction melting, followed by centrifugal casting. The as-cast samples were subjected to hot isostatic pressing and heat treatment consisting of solution annealing in β (Ti-based solid solution) phase field, cooling at a constant rate and stabilization annealing. The microstructure of the alloys consists of α<sub>2</sub> (Ti<sub>3</sub>Al) + γ (TiAl) lamellar grains, single γ phase, coarse Ti<sub>2</sub>AlC particles, and irregular shaped α<sub>2</sub> phase. The increase in the content of C at the expense of decreasing Al in the studied alloys affects solid-state phase transformation temperatures and leads to a decrease in size of grains and primary Ti<sub>2</sub>AlC particles, increase in the volume fraction of reinforcing carbide particles, decrease in the volume fraction of lamellar colonies, and widening of the grain boundaries. Long-term ageing at 800 °C has no effect on the grain size but leads to the formation of Ti<sub>4</sub>Al<sub>3</sub>Nb particles and increase in interlamellar spacing. The Vickers hardness, microhardness of lamellar grains, indentation nanohardness, and elastic modulus of the boundary γ phase decrease during ageing. The Ti-42.6Al-8.7Nb-0.3Ta-2.0C alloy shows improved creep resistance compared to that of Ti-41.0Al-8.7Nb-0.3Ta-3.6C and some reference TiAl-based alloys at a temperature of 800 °C and applied stress of 200 MPa. |
| first_indexed | 2024-03-10T18:09:22Z |
| format | Article |
| id | doaj.art-aa7e1c032689429c877e52053f1b9cad |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-10T18:09:22Z |
| publishDate | 2020-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-aa7e1c032689429c877e52053f1b9cad2023-11-20T08:14:39ZengMDPI AGMolecules1420-30492020-07-012515342310.3390/molecules25153423Comparative Study of Microstructure and Mechanical Properties of Two TiAl-Based Alloys Reinforced with Carbide ParticlesJuraj Lapin0Kateryna Kamyshnykova1Alena Klimova2Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Dúbravská cesta 9, 84513 Bratislava, Slovak RepublicInstitute of Materials and Machine Mechanics, Slovak Academy of Sciences, Dúbravská cesta 9, 84513 Bratislava, Slovak RepublicInstitute of Materials and Machine Mechanics, Slovak Academy of Sciences, Dúbravská cesta 9, 84513 Bratislava, Slovak RepublicMicrostructure and mechanical properties of two TiAl-based alloys with nominal composition Ti-42.6Al-8.7Nb-0.3Ta-2.0C and Ti-41.0Al-8.7Nb-0.3Ta-3.6C (in at.%) were investigated and compared. The alloys were prepared by vacuum induction melting, followed by centrifugal casting. The as-cast samples were subjected to hot isostatic pressing and heat treatment consisting of solution annealing in β (Ti-based solid solution) phase field, cooling at a constant rate and stabilization annealing. The microstructure of the alloys consists of α<sub>2</sub> (Ti<sub>3</sub>Al) + γ (TiAl) lamellar grains, single γ phase, coarse Ti<sub>2</sub>AlC particles, and irregular shaped α<sub>2</sub> phase. The increase in the content of C at the expense of decreasing Al in the studied alloys affects solid-state phase transformation temperatures and leads to a decrease in size of grains and primary Ti<sub>2</sub>AlC particles, increase in the volume fraction of reinforcing carbide particles, decrease in the volume fraction of lamellar colonies, and widening of the grain boundaries. Long-term ageing at 800 °C has no effect on the grain size but leads to the formation of Ti<sub>4</sub>Al<sub>3</sub>Nb particles and increase in interlamellar spacing. The Vickers hardness, microhardness of lamellar grains, indentation nanohardness, and elastic modulus of the boundary γ phase decrease during ageing. The Ti-42.6Al-8.7Nb-0.3Ta-2.0C alloy shows improved creep resistance compared to that of Ti-41.0Al-8.7Nb-0.3Ta-3.6C and some reference TiAl-based alloys at a temperature of 800 °C and applied stress of 200 MPa.https://www.mdpi.com/1420-3049/25/15/3423intermetallicsTiAlcarbidesheat treatmentmicrostructurehardness |
| spellingShingle | Juraj Lapin Kateryna Kamyshnykova Alena Klimova Comparative Study of Microstructure and Mechanical Properties of Two TiAl-Based Alloys Reinforced with Carbide Particles Molecules intermetallics TiAl carbides heat treatment microstructure hardness |
| title | Comparative Study of Microstructure and Mechanical Properties of Two TiAl-Based Alloys Reinforced with Carbide Particles |
| title_full | Comparative Study of Microstructure and Mechanical Properties of Two TiAl-Based Alloys Reinforced with Carbide Particles |
| title_fullStr | Comparative Study of Microstructure and Mechanical Properties of Two TiAl-Based Alloys Reinforced with Carbide Particles |
| title_full_unstemmed | Comparative Study of Microstructure and Mechanical Properties of Two TiAl-Based Alloys Reinforced with Carbide Particles |
| title_short | Comparative Study of Microstructure and Mechanical Properties of Two TiAl-Based Alloys Reinforced with Carbide Particles |
| title_sort | comparative study of microstructure and mechanical properties of two tial based alloys reinforced with carbide particles |
| topic | intermetallics TiAl carbides heat treatment microstructure hardness |
| url | https://www.mdpi.com/1420-3049/25/15/3423 |
| work_keys_str_mv | AT jurajlapin comparativestudyofmicrostructureandmechanicalpropertiesoftwotialbasedalloysreinforcedwithcarbideparticles AT katerynakamyshnykova comparativestudyofmicrostructureandmechanicalpropertiesoftwotialbasedalloysreinforcedwithcarbideparticles AT alenaklimova comparativestudyofmicrostructureandmechanicalpropertiesoftwotialbasedalloysreinforcedwithcarbideparticles |