Kinetics of isothermal structural relaxation in metallic glasses measured by real-time diffraction using synchrotron radiation

Serrated flow model for metallic glasses under compressive loading

“…8 Comparison of model prediction stressstrain curve and experimental results [32] of Zr 35 Ti 30 Co 6 Be 29 metallic glass (strain rate is 10 −3 s −1 ) low value of ∆G * obtained in this study. Furthermore, while the process of structural relaxation is quite different, the value of activation energy for relaxation, E r found in this study is not so far from that obtained using in situ X-ray diffraction method [43,44] .…”

Comment on “Thermal expansion measurements by X-ray scattering and breakdown of Ehrenfest's relation in alloy liquids” [Appl. Phys. Lett. 104, 191907 (2014)]

“…In the last 10 years, a modified Ehrenfest equation (q 3 1 ¼ const v ) was used by several authors for calculation of thermal expansion coefficients of metallic glasses and liquids, 4-6 for the determination of free volume in metallic glasses 4,7 and even more, a fractal character of the atomic structure of metallic glasses was concluded 8 from the analysis of the exponent of q 1 versus v.…”

Isothermal kinetics approach to investigate the structure relaxation of amorphous alloys

“…It is introduced a single perturbation to an equilibrium chemical system, excited by a sudden and dramatic change of an external parameter for example temperature, pressure, and then monitors the rate of change in the concentration of species immediately following the perturbation [19]. This method also would be effective for amorphous alloy structure relaxation in principle and has been introduced to monitor the interatomic distance relaxation of Pd 40 Cu 30 Ni 10 P 20 and Cu 55 Zr 30 Ti 10 Pd 5 metallic glasses [5]. Here we suggest carrying out the isothermal DSC experiments with temperature perturbation, which need a DSC with high temperature changing speed, the best is a flash DSC.…”

“…The energy landscape of amorphous alloy is temperature-dependent, therefore the isothermal relaxation expresses more explicit physical picture than the non-isothermal relaxation and is more suitable for researching the metastable state and the relaxation kinetics. While isothermal analysis is not widely adopted in the investigations of amorphous alloys structure relaxation to date except a few literatures [5,[11][12][13] trying to observe the evolution of viscosity, volume, density or recovered enthalpy in isothermal annealing. The front mentioned important parameters and their evolution in different conditions have never been explored.…”

“…Experimentally, besides thermal analysis, structure relaxation of amorphous alloys also could be explored through several other methods depending on the monitored structure relevant physical property just like viscosity [3], volume [4], mean interatomic distance [5], stress-strain behavior [6] and enthalpy [7]. However, thermal analysis might be the most convenient and effective route since enthalpy can be easily monitored by thermal analysis equipments including DSC, leading to that the non-isothermal DSC might have been a requisite method to study amorphous alloy.…”