The complex DSC analysis of the first crystallization peak of Fe 80 Si 10 B 10 metallic glass

Abstract

The crystallization of Fe 80 Si 10 B 10 glass was studied both by linear heating and isothermal differential scanning calorimetry (DSC). Two well separated crystallization peaks were always observed. On the basis of the classical isothermal Johnson-Mehl-Avrami(JMA) procedure both transient nucleation and transient growth kinetics with the complex exponent n ∼ 2.8 and mean activation energy E∗ JMA = 323 kJ mol −1 were determined for the first crystallization peak. Because for the degree of conversion α > 0.55 E∗(α) dependence was observed, the deconvolution of the isothermal peak into the subsequent JMA nucleation-and-growth and grain-growth effects was used to fit the measured data. Simple JMA kinetics could not be determined for the linear heating first crystallization peak. All these results correlate with structural analysis studies.