About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
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Mechanical Behavior at the Nanoscale VII
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Presentation Title |
Phase-transformation Assisted Twinning in Molybdenum Nanomaterials |
Author(s) |
Linh Vu, zheming Guo, Ali Shargh, Aditya Dey, Niaz Abdolrahim, Hesam Askari |
On-Site Speaker (Planned) |
Niaz Abdolrahim |
Abstract Scope |
Molecular dynamics simulations were conducted to investigate the deformation mechanisms and the correlation between nanostructures and bulk structures in Molybdenum (Mo) nanowires (NWs) and bulk materials with crack tips. The simulations revealed orientation-dependent phase transformations and twinning formation. A bcc-fcc-bcc phase transition was observed to be accompanied by the formation and propagation of twin boundaries in nanowires loaded along <100> direction. However, <110> and <111> loaded NWs and bulk structures did not undergo any phase transformation and exhibited limited dislocation activity before reaching the point of necking. The results indicate that the bcc-fcc-bcc phase transformation is orientation-dependent, occurring specifically under <100>-loaded configurations. Additionally, first principles Density Functional Theory energy calculations demonstrated that the fcc phase is metastable and plays a crucial role in the formation of twin boundaries and the reorientation of the bcc phase. This phenomenon enables the NWs to achieve a larger deformability of up to 80% strain. |
Proceedings Inclusion? |
Planned: |