About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in Ceramic Materials and Processing
|
| Presentation Title |
Phase-field modeling of TiO2 nanocarving via reaction with hydrogen-bearing gas |
| Author(s) |
Alireza Seifi, Sheikh Akbar, Yanzhou Ji |
| On-Site Speaker (Planned) |
Yanzhou Ji |
| Abstract Scope |
TiO2 nanocrystals can be fabricated by carving the TiO2 bulk polycrystals using reductive H2-bearing gases, yielding single-crystal [001] nanowire arrays. However, the origin of the strongly anisotropic nanowire morphology during nanocarving remains largely unexplored. In this study, we formulate a 2-D phase-field model to investigate the TiO2 morphology evolution during nanocarving processes. The model incorporates TiO2 reduction reaction, Ti3+ diffusion, and anisotropies in surface energy, diffusivity and reaction rate. Through systematic simulations in both single- and poly-crystals, we elucidate the roles of different anisotropy factors in nanocrystal morphologies at different carving stages, identifying the strong reaction rate anisotropy as the dominant factor for experimentally observed nanowire morphologies. We further explore the effect of grain misorientation angle, generating a nanocarving morphology map to guide grain orientation control. This study provides insights into microstructure evolution mechanisms during nanocarving and guidances for related microstructure control. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Ceramics, Computational Materials Science & Engineering, Nanotechnology |