Applying Vogel-Fulcher-Tammann relationship in crystallization kinetics of amorphous alloys

The Vogel-Fulcher-Tammann relationship is a generic equation for describing the transport properties of supercooled fragile liquids. Coupling this reasonable equation, a kinetic model is derived in the present work for describing the crystallization kinetics of metallic glass in supercooled liquid region. In the modeling, a constant value for apparent activation energy is substituted by a temperature-dependent one, so that a model is carried forward to describe more general solid-state phase transformation kinetics. Then, recipes of kinetic analysis are proposed, and information about liquid fragility is obtained. Applying the newly proposed model, the evolution of apparent activation energy during the crystallization of many amorphous alloys can be explained. Finally, the crystallization kinetics of Zr55Cu30Al10Ni5 bulk metallic glass, respectively measured by isothermal and non-isothermal differential scanning calorimetry, is studied and interpreted using the present model.