Kinetic Analysis of Crystallization Behaviors in Zn₃₈Mg₁₂Ca₃₂Yb₁₈ Bulk Metallic Glass

The kinetics of crystallization of Zn₃₈Mg₁₂Ca₃₂Yb₁₈ bulk metallic glass was studied by differential scanning calorimetry (DSC) in both non-isothermal and isothermal (at different heating rates) modes. Under isochronal process, theoretical models were adopted to analyze the apparent activation energies for characteristic temperatures. The results indicate that the apparent activation energies for characteristic temperatures in the Zn₃₈Mg₁₂Ca₃₂Yb₁₈ bulk metallic glass by Kissinger model, Flynn-Wall-Ozawa (FWO) model and Augis-Bennett (AB) model are in good agreement with each other. Furthermore, crystallization transformation kinetics during isothermal process was analyzed by the Johnson-Mehl-Avrami (JMA) model. The Avrami exponent n ranges from 3.25 to 4.12 in the isothermal mode. It is noted that the activation energy corresponding to isothermal conditions calculated using Arrhenius equation is larger than the value calculated by the Kissinger method in isochronal conditions, because the energy barrier in isothermal annealing mode is higher than that of isochronal conditions.