About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
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Bulk Metallic Glasses XX
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Presentation Title |
J-80: Evidence of Pre-crystallization Structures in a Zr-based Metallic Glass |
Author(s) |
Amlan Das, Ruitao Zhao, Eric M Dufresne, Yonghao Sun, Robert Maass |
On-Site Speaker (Planned) |
Robert Maass |
Abstract Scope |
Sub-Tg annealing of metallic glasses (MGs) causes structural relaxation and deterioration of mechanical properties but the underlying structural ordering towards crystallization is hard to assess. Here we show the formation of a well-relaxed MG, via a 0.84Tg anneal of an as-cast MG that shows an endothermic pre-Tg process via calorimetry and increased short range ordering (SRO) observed via autocorrelation of HRTEM images. Upon annealing at 0.91Tg, the well-relaxed MG quickly loses the endothermic pre-Tg process and the increased SRO. Continuation of 0.91Tg annealing results in the appearance of a post-Tg endothermic peak and increased SRO above the relaxed levels. Finally, annealing at 0.98Tg causes the crystallization onset to shift to lower temperatures, suggesting that the above-mentioned ordering processes foreshadow crystallization. Annealing is accompanied by x-ray photon correlation spectroscopy and calorimetry, tracking the atomic dynamics and the stored enthalpy (and structure) of the MG towards crystallization. |
Proceedings Inclusion? |
Planned: |
Keywords |
Characterization, |