About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Progress Toward Mechanisms, Thermodynamics, and Kinetics of Phase Transformations: An MPMD/SMD Symposium Honoring John H Perepezko
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| Presentation Title |
Primary Crystallization of High Al-content Metallic Glasses from Quenched-in Nuclei |
| Author(s) |
Paul Voyles |
| On-Site Speaker (Planned) |
Paul Voyles |
| Abstract Scope |
John Perepezko introduced me to the problem of primary crystallization in high Al-content metallic glasses more than 25 years ago. When we met, he had already discovered that glasses like Al<sub>85</sub>Y<sub>7</sub>Fe<sub>5</sub> and Al<sub>92</sub>Sm<sub>8</sub> crystallize to a high density of Al nanocrystals and proposed that the crystals arose from Al crystal nuclei frozen into the glass during quenching. Together, we used fluctuation electron microscopy to find structural evidence of the quenched in nuclei and eventually to measure their size and number density. Perepezko developed a consistent explanation connecting the quenched-in nuclei to the distribution of crystals via nucleation theory. This work ignited my interest in the phase transformations of metallic glasses and led to the recent discovery of two-stage crystallization of a Pd<sub>77.7</sub>Cu<sub>6</sub>Si<sub>16.3</sub> alloy from its supercooled liquid state. |
| Proceedings Inclusion? |
Planned: |