Abstract
Our recent work observed a quite different relaxation pattern, i.e., the abnormal three-steplike sub-Tg relaxation in
CuZrAl GRs[1]. However, the generality and the origin of this remarkable thermodynamic anomaly remain enigmatic.
By hyperquenching strategy, the present work investigated the dependence of thermal history on the sub-Tg enthalpy
relaxation pattern (ERP) of Cu46Zr46Al8 glasses, as well as La55Al25Ni20 for comparisons. It has been found that the
presence of the three-steplike sub-Tg ERP of Cu46Zr46Al8 closely relates to the fictive temperature Tf, whereas no such
anomaly is observed in La55Al25Ni20 GRs. However, the correlation between Tf and the activation energy for initiating the energy releasing during thermal scanning is three-steplike for La55Al25Ni20, revealing the similar phenomenon with the abnormal ERP of Cu46Zr46Al8. These unexpected phenomena have been well explained by the models based on the competitions between the low-temperature and high-temperature clusters used in the terms of the fragile-to-strong (F-S) transition. By analysis on the different chemical feature between Cu46Zr46Al8 and La55Al25Ni20 alloys, it is believed that such anomaly of thermodynamic evolution exists generally in metallic glass-forming liquids, and corresponds to the different extent of the F-S transition.
[1] Lina Hu & Yuanzheng Yue, APL 98(2011) 081904
CuZrAl GRs[1]. However, the generality and the origin of this remarkable thermodynamic anomaly remain enigmatic.
By hyperquenching strategy, the present work investigated the dependence of thermal history on the sub-Tg enthalpy
relaxation pattern (ERP) of Cu46Zr46Al8 glasses, as well as La55Al25Ni20 for comparisons. It has been found that the
presence of the three-steplike sub-Tg ERP of Cu46Zr46Al8 closely relates to the fictive temperature Tf, whereas no such
anomaly is observed in La55Al25Ni20 GRs. However, the correlation between Tf and the activation energy for initiating the energy releasing during thermal scanning is three-steplike for La55Al25Ni20, revealing the similar phenomenon with the abnormal ERP of Cu46Zr46Al8. These unexpected phenomena have been well explained by the models based on the competitions between the low-temperature and high-temperature clusters used in the terms of the fragile-to-strong (F-S) transition. By analysis on the different chemical feature between Cu46Zr46Al8 and La55Al25Ni20 alloys, it is believed that such anomaly of thermodynamic evolution exists generally in metallic glass-forming liquids, and corresponds to the different extent of the F-S transition.
[1] Lina Hu & Yuanzheng Yue, APL 98(2011) 081904
Originalsprog | Engelsk |
---|---|
Publikationsdato | 2013 |
Antal sider | 1 |
Status | Udgivet - 2013 |
Begivenhed | 7th International Discussion Meeting on Relaxations in Complex Systems - Barcelona, Spanien Varighed: 21 jul. 2013 → 26 jul. 2013 |
Konference
Konference | 7th International Discussion Meeting on Relaxations in Complex Systems |
---|---|
Land/Område | Spanien |
By | Barcelona |
Periode | 21/07/2013 → 26/07/2013 |