Dual Role of Nb in Defect-Mediated Strength and Ductility of γ-TiAl Alloys
Fuente:
arXiv
Guardado en:
| Autores principales: | , , , , , , , , , , |
|---|---|
| Formato: | Preprint |
| Publicado: |
2025
|
| Materias: | |
| Acceso en línea: | |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| _version_ | 1866917529535905792 |
|---|---|
| author | Zhao, Zhiqiang Shuang, Siyao Ouyang, Kepeng Yu, Maolin Du, Junping Chu, Liangli Chen, Xiaokai Ogata, Shigenobu Guo, Wanlin Zhang, Zhuhua Zhang, Yong-Wei |
| author_facet | Zhao, Zhiqiang Shuang, Siyao Ouyang, Kepeng Yu, Maolin Du, Junping Chu, Liangli Chen, Xiaokai Ogata, Shigenobu Guo, Wanlin Zhang, Zhuhua Zhang, Yong-Wei |
| contents | The origin of the superior high-temperature strength of γ-TiAl with high Nb addition remains highly controversial, largely due to the unclear role of Nb atoms. Using large-scale hybrid Monte Carlo and molecular dynamics simulations with a self-developed neural network potential,we show that Nb atoms predominantly occupy Ti sites and form short-range order with neighboring Al atoms, but a non-negligible fraction also occupies Al sites (NbAl) and promotes the formation of antisite defects (TiAl). Both the NbAl and TiAl antisites exceptionally reduce stacking fault energies and facilitate deformation twinning, thereby enhancing plasticity. Meanwhile, these substitutional and antisite defects also increase the Peierls stress of both screw and edge dislocations, which hinders dislocation motion to cause pronounced solid-solution strengthening. This work provides mechanistic insights into the dual role of Nb in enhancing both strength and ductility in γ-TiAl and further offers guidance for defect and composition engineering in advanced alloy systems. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2512_00512 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Dual Role of Nb in Defect-Mediated Strength and Ductility of γ-TiAl Alloys Zhao, Zhiqiang Shuang, Siyao Ouyang, Kepeng Yu, Maolin Du, Junping Chu, Liangli Chen, Xiaokai Ogata, Shigenobu Guo, Wanlin Zhang, Zhuhua Zhang, Yong-Wei Materials Science Atomic Physics The origin of the superior high-temperature strength of γ-TiAl with high Nb addition remains highly controversial, largely due to the unclear role of Nb atoms. Using large-scale hybrid Monte Carlo and molecular dynamics simulations with a self-developed neural network potential,we show that Nb atoms predominantly occupy Ti sites and form short-range order with neighboring Al atoms, but a non-negligible fraction also occupies Al sites (NbAl) and promotes the formation of antisite defects (TiAl). Both the NbAl and TiAl antisites exceptionally reduce stacking fault energies and facilitate deformation twinning, thereby enhancing plasticity. Meanwhile, these substitutional and antisite defects also increase the Peierls stress of both screw and edge dislocations, which hinders dislocation motion to cause pronounced solid-solution strengthening. This work provides mechanistic insights into the dual role of Nb in enhancing both strength and ductility in γ-TiAl and further offers guidance for defect and composition engineering in advanced alloy systems. |
| title | Dual Role of Nb in Defect-Mediated Strength and Ductility of γ-TiAl Alloys |
| topic | Materials Science Atomic Physics |
| url | https://arxiv.org/abs/2512.00512 |