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 |
Mechanical Behavior of Marginal Metallic Glasses Governed by Medium-Range Order and Nanoscale Structure |
| Author(s) |
Elif Acun, Fan Sun, İlkay Kalay, Marie-Hélène Berger, Eren Yunus Kalay |
| On-Site Speaker (Planned) |
Elif Acun |
| Abstract Scope |
Aluminum–rare earth marginal metallic glasses (MMGs) exhibit medium-range order (MRO) that governs their unique deformation behavior. Using fluctuation electron microscopy, in-situ TEM tensile straining, and nanoindentation, we investigate how MRO facilitates the formation of fcc-Al nanocrystals (~10 nm) within shear bands during early devitrification. These nanocrystals emerge at adiabatic heat-affected zones, suggesting MRO as a nucleation site and inducing local shear resistance heterogeneity, which act as fracture-delaying mechanisms such as blunting, redirection, and branching. Our nanoindentation reveals pronounced size-dependent hardening effects, supporting the role of nanoscale structural features in deformation. Strain rate–dependent behavior was also observed: at high-strain rates, deformation becomes more homogeneous with amorphous shear band formation due to greater atomic participation; at low strain rates, nanocrystalline shear bands dominate. In this regard, we will present how nanoscale architecture through MRO modulates mechanical response in MMGs. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Mechanical Properties, Characterization, Phase Transformations |