About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
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| Symposium
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Structure-Property Relationships of Bulk Metallic Glasses
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| Presentation Title |
Evidence of Pre-crystallization Structures in a Metallic Glass |
| Author(s) |
Amlan Das, Rui Zhao, Eric Dufresne, Yonghao Sun, Robert Maass |
| On-Site Speaker (Planned) |
Amlan Das |
| Abstract Scope |
Sub-Tg annealing in metallic glasses (MGs) causes structural relaxation and deterioration of mechanical properties. Here we show the formation of a well-relaxed MG, via a 0.84 T_g anneal of an as-cast MG which shows an endothermic pre-Tg process via calorimetry and increased short-range ordering (SRO) observed via autocorrelation of HRTEM images. Upon flash-annealing at 0.91 T_g, the well-relaxed MG loses the endothermic pre-Tg process and the increased SRO. Continuation of 0.91 T_g annealing results in appearance of post-Tg endothermic peak and increased SRO above the relaxed levels. Finally, annealing at 0.98 T_g causes crystallization onset to shift to progressively lower temperatures. Results show the presence of pre-crystallization structural ordering, achieved via sub-Tg annealing and suggest that the above-mentioned ordering foreshadows crystallization. Annealing is accompanied by in-situ x-ray photon correlation spectroscopy showing an aging signature in the atomic dynamics, as well as calorimetry showing the evolution of the endothermic pre-Tg process. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, |