Kinetics of isochronal crystallization in a Fe-based amorphous alloy

In this paper, the kinetics of isochronal differential scanning calorimetry of Fe48Cr15Mo14Y2C15B6 amorphous alloy was analyzed to understand the mechanism of crystallization. The crystallization process constituted of overlapping exothermic transformations occurring from 900 to 1100K with activation energies from 369 to 437 kj mol(-1). Analysis of the mechanism of crystallization under the theoretical framework of the Johnson-Mehl-Avrami-Kolmogorov model revealed that these transformations occurred by three-dimensional growth with either a decreasing nucleation rate or from nuclei that have already been formed. A comparison of the kinetic parameters of nucleation and growth of this alloy with that of Fe50Cr15Mo14C15B6 amorphous alloy showed the effect of yttrium on the increase of thermal stability and impediment of atomic diffusivity leading to decreased nucleation rate in the alloy. (C) 2018 Elsevier B.V. All rights reserved.