heating rate, is much greater than that in characteristic temperature, Compared to other T. ϕ, reported Zr-based metallic glasses, such as = 191 kJ mol−1 and = 171 kJ mol−1 for Eg Ex Zr55Cu30Al10Ni5 BMG [16], the current alloy exhibits higher thermal stability. In addition, the and are considered associated with the nucleation and growth of the crystalline Tx Tp phase precipitated from the glassy alloy, respectively [17]. The results shown in Table 3 imply that the nucleation process is more difficult than the growth process for both first and second stages of crystallization. Eg Ex1 Ep1 Ex2 Ep2 Methods (kJ mol−1) (kJ mol−1) (kJ mol−1) (kJ mol−1) (kJ mol−1) Kissinger 432 251 239 331 289 Ozawa 442 263 250 344 302 According to the concept of fragility introduced by Angell [18], glassy materials can be classified into two groups, namely or glasses. Generally, the “strong” “fragile” “strongly bonded” glass-formers, such as SiO2, exhibit small changes in viscosity during heating, and the temperature dependence of viscosity obeys Arrhenius equation. Conversely, glasses with bonding structure deviate considerably from the Arrhenius behavior. The kinetic “fragile” fragility is defined as the slope of the logarithm of viscosity (or the average structural η relaxation time, dependence on near Tg/T Tg: τ)
heating rate, ϕ, is much greater than that in characteristic temperature, T. Compared to other reported Zr-based metallic glasses, such as Eg = 191 kJ mol−1 and Ex = 171 kJ mol−1 for Zr55Cu30Al10Ni5 BMG [16], the current alloy exhibits higher thermal stability. In addition, the Tx and Tp are considered associated with the nucleation and growth of the crystalline phase precipitated from the glassy alloy, respectively [17]. The results shown in Table 3 imply that the nucleation process is more difficult than the growth process for both first and second stages of crystallization. Methods Eg (kJ mol−1) Ex1 (kJ mol−1) Ep1 (kJ mol−1) Ex2 (kJ mol−1) Ep2 (kJ mol−1) Kissinger 432 251 239 331 289 Ozawa 442 263 250 344 302 According to the concept of fragility introduced by Angell [18], glassy materials can be classified into two groups, namely “strong” or “fragile” glasses. Generally, the “strongly bonded” glass-formers, such as SiO2, exhibit small changes in viscosity during heating, and the temperature dependence of viscosity obeys Arrhenius equation. Conversely, glasses with “fragile” bonding structure deviate considerably from the Arrhenius behavior. The kinetic fragility is defined as the slope of the logarithm of viscosity η (or the average structural relaxation time, τ) dependence on Tg/T near Tg:
Shuang%20thesis.docx