About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Mechanical Response of Materials Investigated through Novel In-situ Experiments and Modeling
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Presentation Title |
High Pressure and In-Situ TEM Deformation of Nanoscale Metallic Interfaces and Precipitates |
Author(s) |
Wendy Gu, Abhinav Parakh, Mehrdad Kiani |
On-Site Speaker (Planned) |
Wendy Gu |
Abstract Scope |
Interfaces, precipitates, and defects govern the properties of nanostructured metals and lightweight alloys. High pressure techniques are used to understand deformation during shock, impact, and ballistic loading, which include pressures of tens of GPa to Mbar. Diamond anvil cells (DAC) are used to compress lightweight alloys under quasi-hydrostatic and non-hydrostatic stress. X-ray diffraction is used to monitor structural changes in-situ, and post-compression TEM is used to directly image these changes. We find that non-hydrostatic pressure leads to a significant increase in defect density, elevated strength and the nucleation and growth of precipitates in precipitate hardened Al7075. Hydrostatic pressure leads to extensive detwinning in nanotwinned alloys with aligned twins. In-situ TEM experiments are performed on individual grain boundaries within Au bicrystals. We find that failure in these bicrystals does not seem to depend on misorientation angle or grain boundary energy, but is sensitive to surface imperfections and dislocation activity. |
Proceedings Inclusion? |
Planned: |
Keywords |
Characterization, Mechanical Properties, Aluminum |