Co68.5Fe4Si10B17.5非晶合金晶化动力学行为研究

Study on Crystallization Kinetics of Co68.5Fe4Si10B17.5 Amorphous Alloys

采用示差热分析(DSC)研究了旋铸急冷法在大气环境中制备出的Co68.5Fe4Si10B17.5非晶合金的非等温晶化的动力学行为。研究发现:在连续加热条件下,随升温速率的加快,合金的特征温度Tg,Tx,Tp均向高温区移动。当分别采用晶化开始温度和峰值温度时,所得非晶合金的激活能并不是稳定值。用Doyle-Ozawa方法计算出的激活能值比Kissinger法计算出的激活能值要大。非晶态Co68.5Fe4Si10B17.5合金的晶化百分比与退火温度和退火时间的关系曲线均呈S型。随加热速度的增加,非晶合金的晶化百分比与温度的关系曲线向高温处移动。

Co68. 5Fe4Si10B17.5 amorphous alloys were prepared by a single roller melt-spinning technique in an air atmosphere. The crystallization kinetics were studied based on differential scanning calorimetric （DSC） measurements were performed on the exothermic peaks of the sample. One was non-isothermal crystallization kinetics at constant heating rate, which could be analyzed by the Kissinger and Doyle-Ozawa method. From the non-isothermal DSC thermo-gram, it could be seen that the value of crystallization peak temperature increased with increasing heating rate. The apparent active energy was variation suggested by Kissinger method with Ts, Tx and Tp. The average active energy suggested by Doyle-Ozawa was higher than that obtained by Kissinger method. The crystallized fraction x as a function of temperature at different heating rates exhibited ＂S＂ type. It moved to high temperature with increasing heating rate.