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采用单辊急冷法制备了Fe71Nb6B23非晶薄带,并用差示扫描热分析法(DSC)研究了该非晶合金的变温晶化动力学。从DSC曲线可知,玻璃化转变温度Tg、晶化起始温度Tx和晶化峰值温度Tp均随着升温速率的增加向高温方向移动,这些特征温度均具有明显的动力学效应。分别利用Kissinger方程和Ozawa方程计算了该Fe基非晶薄带的玻璃化转变激活能Eg、晶化激活能Ex和激活能Ep,并解释了此非晶合金具有高的热稳定性的热力学机制。结果表明:两种方程计算得出的Ex均大于Ep,表明该合金的形核过程比晶粒长大更为困难;晶化的动力学效应较玻璃化转变更为明显。
The amorphous Fe71Nb6B23 ribbon was prepared by single roll rapid cooling method. The crystallization kinetics of the amorphous alloy was investigated by differential scanning calorimetry (DSC). From the DSC curve, the glass transition temperature Tg, the crystallization onset temperature Tx and the crystallization peak temperature Tp all move toward the high temperature with the increase of the heating rate. These characteristic temperatures all have obvious kinetic effects. The glass transition activation energy Eg, the activation energy Ex and the activation energy Ep were calculated by Kissinger equation and Ozawa equation respectively. The thermodynamic mechanism of this amorphous alloy with high thermal stability was also explained . The results show that Ex calculated by the two equations is greater than Ep, indicating that the nucleation process of the alloy is more difficult than the grain growth; the kinetic effect of crystallization is more obvious than the glass transition.