Effect of minor addition on dynamic mechanical relaxation in ZrCu-based metallic glasses
The dynamic mechanical behavior of Zr50-xCu34Ag8Al8Pdx (x = 0 and 2) bulk metallic glasses was probed by mechanical spectroscopy. The results suggest that microalloying retards the relaxation dynamics. The physical aging was analyzed considering a model based on the variation of the concentration of...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/336930 |
| Acceso en línea: | https://hdl.handle.net/2117/336930 https://dx.doi.org/10.1016/j.jnoncrysol.2020.120496 |
| Access Level: | acceso abierto |
| Palabra clave: | Metallic glasses Metallic glass Mechanical relaxation Structural heterogeneity Physical model Vidres metàl·lics Àrees temàtiques de la UPC::Física |
| Sumario: | The dynamic mechanical behavior of Zr50-xCu34Ag8Al8Pdx (x = 0 and 2) bulk metallic glasses was probed by mechanical spectroscopy. The results suggest that microalloying retards the relaxation dynamics. The physical aging was analyzed considering a model based on the variation of the concentration of flow units and the Kohlrausch-Williams-Watts (KWW) equation. In the current study, the characteristic parameters of the two models, ßc and ßaging, reflect the faster annihilation of flow units at higher temperature and the increase of dynamic heterogeneity with temperature, respectively. The mechanical relaxation spectrum was also analyzed. Based on the KWW equation and the quasi-point defect model, replacing Zr with a small amount of Pd can slightly increase the dynamic inhomogeneity and reduce the defect concentration. The analysis according to the HN function suggests that the addition of Pd increases the relaxation time. However, it does not significantly alter the shape of the relaxation time distribution. |
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