Isochronal and isothermal crystallization in Zr55Cu30Ni5 Al10 bulk metallic glass

Non-isothermal crystallization transformation kinetics and isothermal crystallization kinetics in super-cooled liquid region (SLR) in Zr55Cu30Ni5Al10 bulk metallic glasses were studied by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). In isochronal mode, the average values of activation energy in Zr55Cu30Ni5Al10 bulk metallic glass determined by different models (Kissinger method, Flynn-Wall-Ozawa method and Augis-Bennett method) are in good agreement with each other. In addition, the isothermal transformation kinetics in Zr55Cu30Ni5Al10 bulk metallic glasses was described by the Johnson-Mehl-Avrami (JMA) model. For Zr55Cu30Ni5Al10 bulk metallic glass, the Avrami exponent n ranges from 2.2 to 2.9, indicating that crystallization mechanism in the bulk metallic glass was mainly diffusion-controlled; crystal growth is controlled by long range ordering diffusion in three-dimensional growth during isothermal crystallization process. The average value of activation energy in Zr55Cu30Ni5Al10 bulk metallic glass is 469 kJ/mol in isothermal transformation process.