Non-isothermal crystallization kinetics of FeZrB amorphous alloy

The non-isothermal crystallization kinetics of amorphous Fe(78)Zr(7)B(15) alloy is investigated to shed light on the crystallization mechanism. The crystallization of amorphous Fe(78)Zr(7)B(15) alloy exhibits two distinct steps. The apparent activation energy of the first (E(a1)) and second step crystallization (E(a2)) are determined by Kissinger and Ozawa equations. The comparative value of E(a1) < E(a2) implies that the first step crystallization is easier to be occurred. The calculation based on Kissinger-Akahira-Sunose (KAS) model suggests that the local activation energy [E(x)] decreases with crystallized volume fraction (x). The Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation is extended to non-isothermal transformation to probe the transformation mechanism. The results show that the crystallization of the first and second step is dominated by low and three dimensional nucleation and growth, respectively. Both nucleation rates of these two steps increase firstly and then reduce. (C) 2011 Elsevier B.V. All rights reserved.