About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
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Mechanical Behavior at the Nanoscale VIII
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| Presentation Title |
In situ TEM investigation of the effect of stable grain boundaries on plastic deformation mechanisms and mechanical properties of Pt-Au alloys |
| Author(s) |
Yichen Yang, Kyle Dorman, Kunqing Ding, Remi Dingreville, Brad Boyce, Ting Zhu, Josh Kacher, Olivier Pierron |
| On-Site Speaker (Planned) |
Olivier Pierron |
| Abstract Scope |
Au solute atoms lock the grain boundaries (GBs) of nanocrystalline Pt. Here we quantify how this pinning affects plasticity in 100 nm-thick nanocrystalline Pt and Pt-10Au with our MEMS-based quantitative in situ TEM technique that enables stress, strain, and physical activation volume measurements. Pure Pt yields at ~1.4 GPa and starts to soften beyond a strain of 3%. Instead, Pt-10Au yields at 1.8 GPa with no softening. Concurrent in situ TEM observations and 4D-STEM orientation mapping confirm that GB migration, prominent in Pt (that undergoes significant grain coarsening upon deformation), does not occur in Pt-10Au. Plastic straining in the alloy is carried solely by repeated dislocation emission and glide. This mechanistic shift is reflected in a two-fold increase in physical activation volume, from 4 (for Pt) to 8 b3(for Pt-10Au). These results can be compared to our atomistic simulations quantifying the activation volume of specific GB-mediated unit processes. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Mechanical Properties, Thin Films and Interfaces, Modeling and Simulation |