On the use of classical JMAK crystallization kinetic theory to describe simultaneous processes leading to the formation of different phases in metals

Abstract

The classical theory of Johnson–Mehl–Avrami–Kolmogorov (JMAK) is widely used to describe the kinetics of crystallization even when the premises required for its application are not strictly fulfilled. In this paper we propose a procedure to obtain the JMAK parameters of the independent transformations that simultaneously occur during a crystallization process (e.g. leading to the formation of several crystalline phases). The predictions of the analysis have been used to describe the crystallization process of two amorphous alloys with Fe90Zr10 and (Fe0.7Co0.3)Zr10 composition, respectively, which consists of two overlapped processes ascribed to the formation of α-Fe(Co) phase and a Zr-rich intermetallic.