Isochronal and isothermal crystallization kinetics of amorphous Fe-based alloys

Abstract Using the differential scanning calorimetry (DSC), the isochronal and isothermal crystallization kinetics of amorphous Fe 61 Co 9− x Zr 8 Mo 5 W x B 17 ( x  = 0 and 2) ribbons was investigated by the Kissinger equation and by the Kolmogorov–Johnson–Mehl–Avrami and Ranganathan–Heimendahl equations, respectively. The results show that tungsten can improve the activation energy E 1 K for the first crystallization in the isochronal annealing process and activation energy E n for the nucleation in the isothermal annealing process, which can be ascribed to the dissolution of tungsten in the amorphous phase. Meanwhile, tungsten can decrease the activation energy E 2 K for the second crystallization in the isochronal annealing process and growth activation energy E g in the isothermal annealing process, which is possibly associated with the formation of W-rich compound after the early nucleation process.