| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Functional Nanomaterials 2020: Translating Innovation into Pioneering Technologies
|
| Presentation Title |
Metastable Phase Transformation and Deformation Twinning Induced Hardening-stiffening Mechanism in Silicon Nanoparticles |
| Author(s) |
Yu Hong, Ning Zhang, Mohsen Asle Zaeem |
| On-Site Speaker (Planned) |
Ning Zhang |
| Abstract Scope |
The compressive mechanical responses of silicon nanoparticles with respect to crystallographic orientations are investigated by atomistic simulations. Superelastic and abrupt hardening-stiffening behaviors are revealed in [110]-, [111]- and [112]-oriented nanoparticles. The obtained hardness values of these particles are in good agreement with the experimental results. In particular, [111]-oriented particle is extremely hard since its hardness (∼33.7 GPa) is almost three times greater than that of the bulk silicon (∼12 GPa). To understand the underlying deformation mechanisms, metastable phase transformation is detected in these particles. Deformation twinning of the metastable phase are observed to account for the early hardening-stiffening behavior in [110]-oriented particles. The twin phase then coalescences and undergoes compression to resist further deformation, and leads to the subsequent re-hardening and re-stiffening events. The same metastable phase is also detected in [111]- and [112]-oriented particles. A size effect on hardness of silicon nanoparticles, i.e., “smaller is harder”, is revealed. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |