Microstructure evolution and phase transformation mechanism of Ti–46Al–8Nb–2.5V alloy based on phase transformation geometric models
The microstructure of conventionally solidified and rapidly solidified Ti–46Al–8Nb-2.5V alloys was analyzed with phase transformation geometric models, revealing the phase transformation mechanisms. The β→α→γ phase transformation processes follow Burgers and Blackburn orientation relationships (ORs)...
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| Format: | Article |
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Elsevier
2023-11-01
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| Series: | Journal of Materials Research and Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785423028089 |
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| author | Shouzhen Cao Jianchao Han Hongfeng Wang Shulong Xiao Yuyong Chen Yi Jia |
| author_facet | Shouzhen Cao Jianchao Han Hongfeng Wang Shulong Xiao Yuyong Chen Yi Jia |
| author_sort | Shouzhen Cao |
| collection | DOAJ |
| description | The microstructure of conventionally solidified and rapidly solidified Ti–46Al–8Nb-2.5V alloys was analyzed with phase transformation geometric models, revealing the phase transformation mechanisms. The β→α→γ phase transformation processes follow Burgers and Blackburn orientation relationships (ORs), respectively, from which the calculated transformation between the β/β0 and γ phases follow K–S OR. Whlie, the direct β/β0→γ phase transformation can be directly observed in the microstructure, which follows a variety of ORs, mainly following the K–S OR but also following the N–W or Bain ORs, most of which deviate from the strict ORs. In cases where N–W and Bain ORs are followed, there is a large dislocation spacing between the habit planes of the β/β0 and γ phases, resulting in low static energy at the interface and narrow elongated morphology of precipitated phases. Conversely, when following K–S OR for β/β0 → γ phase transformation, interfacial migration energy is relatively lower and grain precipitated phases is larger. The rapidly solidified microstructure of Ti–46Al–8Nb-2.5V alloy consists of the massive α2 phase, massive γ phase, and basket-weave β0 phase closely resembling those found in β-type titanium alloys. After annealing at service temperature, the rapidly solidified alloy forms a microstructure highly similar to that of conventionally solidified TiAl alloy. Various metastable phases, such as the Ti2Al, L12 and Ti1.4Al phases, precipitate in the blocky γ phase, which provides a theoretical basis for studying the phase transformations of TiAl alloys in service. |
| first_indexed | 2024-03-07T23:23:10Z |
| format | Article |
| id | doaj.art-b52ce6da32ac4b61accdc2b9788cfac6 |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-03-07T23:23:10Z |
| publishDate | 2023-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-b52ce6da32ac4b61accdc2b9788cfac62024-02-21T05:27:34ZengElsevierJournal of Materials Research and Technology2238-78542023-11-012761356147Microstructure evolution and phase transformation mechanism of Ti–46Al–8Nb–2.5V alloy based on phase transformation geometric modelsShouzhen Cao0Jianchao Han1Hongfeng Wang2Shulong Xiao3Yuyong Chen4Yi Jia5School of Electrical and Mechanical Engineering, Huangshan University, Huangshan 245021, ChinaAdvanced Metal Composite Forming Technology and Equipment Engineering Research Center of Ministry of Education, Taiyuan 030024, China; Corresponding author. Advanced Metal Composite Forming Technology and Equipment Engineering Research Center of Ministry of Education, Taiyuan 030024, China.School of Electrical and Mechanical Engineering, Huangshan University, Huangshan 245021, ChinaSchool of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, ChinaSchool of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, ChinaAdvanced Metal Composite Forming Technology and Equipment Engineering Research Center of Ministry of Education, Taiyuan 030024, ChinaThe microstructure of conventionally solidified and rapidly solidified Ti–46Al–8Nb-2.5V alloys was analyzed with phase transformation geometric models, revealing the phase transformation mechanisms. The β→α→γ phase transformation processes follow Burgers and Blackburn orientation relationships (ORs), respectively, from which the calculated transformation between the β/β0 and γ phases follow K–S OR. Whlie, the direct β/β0→γ phase transformation can be directly observed in the microstructure, which follows a variety of ORs, mainly following the K–S OR but also following the N–W or Bain ORs, most of which deviate from the strict ORs. In cases where N–W and Bain ORs are followed, there is a large dislocation spacing between the habit planes of the β/β0 and γ phases, resulting in low static energy at the interface and narrow elongated morphology of precipitated phases. Conversely, when following K–S OR for β/β0 → γ phase transformation, interfacial migration energy is relatively lower and grain precipitated phases is larger. The rapidly solidified microstructure of Ti–46Al–8Nb-2.5V alloy consists of the massive α2 phase, massive γ phase, and basket-weave β0 phase closely resembling those found in β-type titanium alloys. After annealing at service temperature, the rapidly solidified alloy forms a microstructure highly similar to that of conventionally solidified TiAl alloy. Various metastable phases, such as the Ti2Al, L12 and Ti1.4Al phases, precipitate in the blocky γ phase, which provides a theoretical basis for studying the phase transformations of TiAl alloys in service.http://www.sciencedirect.com/science/article/pii/S2238785423028089Titanium aluminideMicrostructure evolutionPhase transformation geometric modelsMetastable phase |
| spellingShingle | Shouzhen Cao Jianchao Han Hongfeng Wang Shulong Xiao Yuyong Chen Yi Jia Microstructure evolution and phase transformation mechanism of Ti–46Al–8Nb–2.5V alloy based on phase transformation geometric models Journal of Materials Research and Technology Titanium aluminide Microstructure evolution Phase transformation geometric models Metastable phase |
| title | Microstructure evolution and phase transformation mechanism of Ti–46Al–8Nb–2.5V alloy based on phase transformation geometric models |
| title_full | Microstructure evolution and phase transformation mechanism of Ti–46Al–8Nb–2.5V alloy based on phase transformation geometric models |
| title_fullStr | Microstructure evolution and phase transformation mechanism of Ti–46Al–8Nb–2.5V alloy based on phase transformation geometric models |
| title_full_unstemmed | Microstructure evolution and phase transformation mechanism of Ti–46Al–8Nb–2.5V alloy based on phase transformation geometric models |
| title_short | Microstructure evolution and phase transformation mechanism of Ti–46Al–8Nb–2.5V alloy based on phase transformation geometric models |
| title_sort | microstructure evolution and phase transformation mechanism of ti 46al 8nb 2 5v alloy based on phase transformation geometric models |
| topic | Titanium aluminide Microstructure evolution Phase transformation geometric models Metastable phase |
| url | http://www.sciencedirect.com/science/article/pii/S2238785423028089 |
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