Thermoanalytical study of crystallization process in metallic glass of Co69Fe3Si18B10

The non-isothermal crystallization kinetics of amorphous Co69Fe3Si18B10 metallic glass has been studied using various thermal analytical models. The DSC curve of amorphous sample in a constant heating rate experiment showed the appearance of two crystallization events at peak temperatures 761 and 803 K, respectively. The activation energy for the secondary crystallization process was found to be lower compared to that of primary process which indicated the ease of secondary crystallization process from modified matrix due to the evolution of the primary phase. The activation energy remained constant during the primary crystallization process over the range of crystallization fraction (0.1-0.9), however, the local Avrami exponent for this crystallization process manifested complex variation with crystallized volume fraction. The validity of the JMA model for the primary crystallization process has been studied. This crystallization process was found to show autocatalytic behavior which has been given a mathematical description using a two-parameter model of Sestak-Berggren.