About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
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Defects and Interfaces: Modeling and Experiments
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Presentation Title |
Plastic Co-deformation of Aluminum and Silicon at Nano-scale |
Author(s) |
Arkajit Ghosh, Wenqian Wu, Bibhu Prasad Sahu, Jian Wang, Amit Misra |
On-Site Speaker (Planned) |
Arkajit Ghosh |
Abstract Scope |
Nano-scale eutectics, like rapidly solidified Al-Si alloys, show enhanced yield strength and strain hardening due to dislocation activities in ultrafine soft phase (Al) channels. However, the limited plasticity stems from cracking in the hard phase (Si). To maximize plasticity in these high-strength microstructures, it's crucial to suppress cracking and enable plastic co-deformation of the disparate phases. By combining laser rapid solidification and 0.2 wt% Sr modification, fully eutectic Al-Si microstructures with heavily twinned Si nano-fibers were synthesized, which exhibit remarkable properties: high hardness (~2.9 GPa), high compressive strength (~840 MPa), and stable plastic flow up to ~26% strain. Notably, the chemically-modified Si(Sr) fibers didn't crack during deformation. Instead, a high density of stacking faults indicates partial-dislocation-mediated-plasticity. The key mechanisms behind crack-suppression and activation of partial dislocations in room-temperature-deformed Si are attributed to the nanoscale fiber geometry, reduced aspect ratio, and lowered Peierls barrier in the chemically-modified, nano-twinned Si fibers. |
Proceedings Inclusion? |
Planned: |
Keywords |
Mechanical Properties, Characterization, Aluminum |