【摘要】 用直流高密度电脉冲处理Fe78B13 Si9非晶合金 ,并用穆斯堡尔及透射电子显微镜 (TEM )研究了电脉冲处理试样的结构。实验结果表明 ,在所用电脉冲参数下 ,Fe78B13 Si9非晶合金在温度高于 40 0℃时即可发生纳米晶化 ,根据穆斯堡尔参数分析 ,两个晶态相被确定为α Fe(Si)和Fe2 B ,界面相具有低原子密度和展宽的原子间距分布 ,既长程序又无非晶态短程序 ,其原因在于 ,电脉冲作用下的纳米晶化 ,淬态试样中过剩的自由体积未经充分的衰减 ,而是被推移至剩余非晶以至界面内 ,故不同于用通常的等温退火方法由非晶合金制备的纳米晶合金。更多还原

【Abstract】 The amorphous Fe 78 B 13 Si 9 alloy has been treated by high current density electropulsing and the structure of the electropulsed samples has been studied using Mssbauer spectroscopy and transmission electron microscopy (TEM).The experimental results show that nanocrystallization in the amorphous of Fe 78 B 13 Si 9 sample can occur at temperature of 400℃ or above under the used electropulse parameters.Based on the analysis of Mssbauer parameters,two crystalline phases are ascribed to be α Fe(Si) and t Fe 2B.The intergranular phase is characterized by a lower atom density and an extended spacing distribution with neither long range order nor short range order.It is originated from the pulse induced nanocrystallization,in which the excess free volume is not fully attenuated,but is pushed to the residual amorphous phase till further intergranular boundaries, therefore different from the nanocrystalline prepared by the conventional isothermal annealing method.更多还原