Determination of kinetic parameters during isochronal crystallization of Ti₄₀Zr₂₅Ni₈Cu₉Be₁₈ metallic glass

The isochronal crystallization kinetics of Ti₄₀Zr₂₅Ni₈Cu₉Be₁₈ metallic glass has been studied by differential scanning calorimetry (DSC) at various heating rates. The changeable activation energies with crystalline fraction are determined by the Kissinger-Akahira-Sunose (KAS) method without assuming any kinetic model. Results obtained by directly fitting the experimental DSC data to the calculated DSC curves indicate that the crystallization process of Ti₄₀Zr₂₅Ni₈Cu₉Be₁₈ metallic glass cannot be satisfactorily described by the Johnson-Mehl-Avrami (JMA) model. Kinetic parameters of the both crystallization events are significantly influenced by the heating rate. Simulation results indicate that the Sestak-Berggren (SB) model is more suitable to describe the crystallization kinetics of this Ti-based metallic glass. Reasons of the deviations from the JMA model are also discussed.