Please use this identifier to cite or link to this item: doi:10.22028/D291-27485
Title: On the Fragility of Bulk Metallic Glass Forming Liquids
Author(s): Gallino, Isabella
Language: English
Title: Entropy
Volume: 19
Issue: 9
Publisher/Platform: MDPI
Year of Publication: 2017
DDC notations: 600 Technology
Publikation type: Journal Article
Abstract: In contrast to pure metals and most non-glass forming alloys, metallic glass-formers are moderately strong liquids in terms of fragility. The notion of fragility of an undercooling liquid reflects the sensitivity of the viscosity of the liquid to temperature changes and describes the degree of departure of the liquid kinetics from the Arrhenius equation. In general, the fragility of metallic glass-formers increases with the complexity of the alloy with differences between the alloy families, e.g., Pd-based alloys being more fragile than Zr-based alloys, which are more fragile than Mg-based alloys. Here, experimental data are assessed for 15 bulk metallic glasses-formers including the novel and technologically important systems based on Ni-Cr-Nb-P-B, Fe-Mo-Ni-Cr-P-C-B, and Au-Ag-Pd-Cu-Si. The data for the equilibrium viscosity are analyzed using the Vogel–Fulcher–Tammann (VFT) equation, the Mauro–Yue–Ellison–Gupta–Allan (MYEGA) equation, and the Adam–Gibbs approach based on specific heat capacity data. An overall larger trend of the excess specific heat for the more fragile supercooled liquids is experimentally observed than for the stronger liquids. Moreover, the stronger the glass, the higher the free enthalpy barrier to cooperative rearrangements is, suggesting the same microscopic origin and rigorously connecting the kinetic and thermodynamic aspects of fragility.
DOI of the first publication: 10.3390/e19090483
Link to this record: urn:nbn:de:bsz:291--ds-274851
ISSN: 1099-4300
Date of registration: 16-Jan-2020
Faculty: NT - Naturwissenschaftlich- Technische Fakultät
Department: NT - Materialwissenschaft und Werkstofftechnik
Collections:SciDok - Der Wissenschaftsserver der Universität des Saarlandes

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