高强脉冲电流工艺参数对Fe基非晶合金纳米晶化的影响

Effects of Processing Parameters of High-Density Pulsing Current on the Nanocrystallization of an Fe-Based Amorphous Alloy

高强脉冲电流能使Fe基非晶合金在低于非晶转变温度70～100K的条件下实现快速晶化。脉冲频率和处理时间对Fe基非晶合金晶化过程有显著影响。在高强脉冲电流的作用下,随着处理时间的增加,Fe基非晶合金先发生结构弛豫,然后在某一临界处理时间之后发生快速晶化,析出大量的α-Fe(Si)纳米相,最后晶化过程趋于稳定。提高脉冲频率f,可以有效缩短临界处理时间,但不改变Fe基非晶合金纳米晶化过程中显微硬度的变化趋势。与等温退火工艺相比,高强脉冲电流处理是一种高效的非晶合金快速晶化方法。

It has been found that Fe73.5Cu1Nb3Si13.5B9 amorphous ribbons can be rapidly nanocrystallized by high-density pulsing current at a temperature of 70～100 K lower than the glass transition temperature. The pulsing frequency and processing time have significant effects on the nanocrystallization of the studied amorphous alloy. Under the action of high-density pulsing current, the structural relaxation is induced firstly, and then the precipitation of abundant α-Fe（Si） nanocrystals occurs at a certain critical processing time. Moreover, the critical processing time can be evidently reduced by increasing the pulsing frequency. It shows that high-density pulsing current is an effective way for rapid nanocrystallization of the studied amorphous alloy, comparing with the isothermal annealing.