About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
American Ceramic Society Journal Awards Symposium
|
| Presentation Title |
Room-temperature plastic deformation of polycrystalline SrTiO3 via dislocations |
| Author(s) |
Chukwudalu Okafor, Kuan Ding, Oliver Preuß, Neamul Khansur, Wolfgang Rheinheimer, Xufei Fang |
| On-Site Speaker (Planned) |
Chukwudalu Okafor |
| Abstract Scope |
Dislocations in ceramics find renewed interest in tuning mechanical and functional properties, but most studies have focused on single crystals. Polycrystalline samples offer broader applications if dislocations can be effectively introduced. However, grain boundaries (GBs) in polycrystalline materials hinder bulk plastic deformation, leading to dislocation pile-up and/or cracking due to limited independent slip systems in ceramics at room temperature. We used cyclic Brinell indentation to investigate near-surface plasticity in polycrystalline SrTiO3. Dislocation etch-pit analysis reveals that plastic deformation initiates within grains, at GBs, and pores at GB triple junctions. Plastic deformability increases with increased cycle number, as validated on single-crystal and polycrystalline SrTiO3. We also identified a grain-size dependence on plastic deformation. Furthermore, the plastic zone size can be extended arbitrarily via cyclic Brinell scratching. These findings are further extended to other ceramics that exhibit good deformability at room temperature for efficient dislocation engineering. |