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 |
How Surfaces Affect the Shape, Elastic Response, and Deformation Behavior of Small Metal Nanoparticles |
Author(s) |
Tevis D.B. Jacobs, Ruikang Ding, Ingrid Padilla Espinosa, Soodabeh Azadehranjbar, Ashlie Martini |
On-Site Speaker (Planned) |
Tevis D.B. Jacobs |
Abstract Scope |
In this talk, I will discuss three years of published and unpublished work using in situ TEM compression testing to understand how a nanoparticle’s “bulk” behavior is controlled by its surface. First, I will discuss the size-dependent shape of single-digit-nm platinum nanoparticles, and how surface energy controls the distributions of shapes that are observed. Second, when those particles of various shapes are compressed, we show how to understand their size-dependent stiffness. We use atomistic simulations and in situ compression testing to show to disentangle geometric effects such as spatial variations in stress from surface effects, where the undercoordinated surface atoms have meaningfully different bond stiffnesses. Finally, in the permanent-deformation regime, we show how the surface weakens the nanoparticle. Moving beyond the traditional Coble-creep-like model, we reveal the how mechanical deformation of small particles is governed by a competition between surface nucleation of dislocations and surface-mediated shape change. |
Proceedings Inclusion? |
Planned: |
Keywords |
Mechanical Properties, Nanotechnology, Modeling and Simulation |