About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Bulk Metallic Glasses XX
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Presentation Title |
Structure-Dynamics Relationships in Cryogenically Deformed Bulk Metallic Glass |
Author(s) |
Jurgen H. Eckert, Florian Spieckermann, Baran Sarac, Daniel Sopu |
On-Site Speaker (Planned) |
Jurgen H. Eckert |
Abstract Scope |
The atomistic mechanisms governing aging and rejuvenation in glasses are still unclear. In-situ X-ray diffraction allows to investigate the structural rearrangements during annealing from 77 K up to crystallization in Cu-Zr-Al-Hf-Co bulk metallic glass, rejuvenated by high pressure torsion at cryogenic and room temperature. The configurational entropy calculated from X-ray pair correlation functions gives a structural footprint of deformation-induced rejuvenation. With synchrotron radiation, temperature and time resolutions comparable to calorimetry are possible, allowing to correlate changes in atomic configuration to calorimetric signals and to attribute those to changes of dynamic and vibrational α-, β- and γ-relaxations. The results suggest that the structural footprint of the β-transition is related to entropic relaxation with first-order characteristics. Dynamic mechanical analysis reveals that non-reversible structural rearrangements are preferentially activated throughout the β-transition. The low-temperature γ-transition mostly triggers reversible deformations with a change of slope in the entropic footprint suggesting second-order characteristics. |
Proceedings Inclusion? |
Planned: |