Analysis of crystallization process of metglas 2605SC by dilatometer

Abstract

In this work, the crystallization process of an amorphous metal was analyzed precisely by dilatometer. The length-change of Metglas 2605SC during isothermal annealing at temperatures of 400 °C – 450 °C was measured with a dilatometer. On the crystallization process of this amorphous metal, three stages were observed. From the Johnson-Mehl analysis, the time exponents n and the activation energies E a of these three stages were obtained, which were ∼1.0 and 3.9 eV on the first stage, ∼2.5 and 3.2 eV on the second stage, and ∼1.5 and 3.3 eV third stage, respectively. It is considered that the first stage corresponds to the diffusion controlled growth of α-iron dendrites (cylinder) only to the axis direction, and that the second stage corresponds to the precipitation and growth of intermetallic compounds in addition to α-iron. On the third stage, a fixed number of particles grow by diffusion control.