| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Mechanical Behavior at the Nanoscale V
|
| Presentation Title |
N-9: Grain Boundary Engineering Leading to Enhanced Mechanical Properties of Superhard Boron Carbide |
| Author(s) |
Qi An, Dezhou Guo, Kolan Madhav Reddy |
| On-Site Speaker (Planned) |
Qi An |
| Abstract Scope |
To improve the mechanical properties of superstrong B4C, we investigated how grain boundaries (GBs) determine the deformation and failure mechanism of B4C. The deformation and failure mechanism of nanocrystalline B4C (n-B4C) were studied using the reactive force field (ReaxFF) simulations. We found that the main deformation mechanism of nanocrystalline B4C is grain boundary sliding, leading to a reverse Hall-Petch relationship. This GB sliding triggers the amorphous shear band formation at predistorted icosahedral GB regions with initiation of cavitation within the amorphous bands. Our simulation results are validated by the nanoindentation experiments in which an intergranular amorphous GB phase was observed due to GB sliding. Although most GB sliding events in our ReaxFF simulations lead to the intergranular amorphization, we do observe one intragranular amorphization initiates from grain boundaries (GBs) and propagates along the rhombohedral (011)[2-1-1] slip system. This leads to the amorphous shear band formation and intragranular amorphization. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |