About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
|
| Presentation Title |
Dislocation–Grain boundary interactions in bi-crystal and polycrystalline strontium titanate |
| Author(s) |
Xufei Fang, Chukwudalu Okafor, Atsutomo Nakamura |
| On-Site Speaker (Planned) |
Xufei Fang |
| Abstract Scope |
For potential wide applications of ceramics for dislocation-tuned properties, it is pertinent to achieve dislocation engineering in polycrystalline ceramics. However, grain boundaries (GBs) in general are effective barriers for dislocation glide and slip transfer, often resulting in crack formation when plastic deformation is attempted. To develop strategies for crack suppression, it is critical to understand the fundamental processes for dislocation–GB interaction. Here, we adopt a model system of bi-crystal SrTiO3 with a 4-degree tilt and a sigma-5 GB and develop the Brinell indentation approach to generate plastic zone at mesoscale without crack formation, allowing for direct assessment of GB responses to dislocations in bulk sample at room temperature. Together with dislocation etch pits analysis and observations in electron microscopy, we observe dislocation pileup, absorption, and transmission, depending on the GB types in SrTiO3. Our findings on bicrystals are further correlated with plastic deformation of polycrystalline SrTiO3 at room temperature. |