低频脉冲磁场方法处理铁基非晶合金的内耗研究

INVESTIGATION OF INTERNAL FRICTION IN IRON BASE AMORPHOUS ALLOYS TREATED BY LOW FREQUENCY PULSE MAGNETIC FIELD METHOD

利用低频脉冲磁场处理铁基非晶合金的方法得到综合性能更好的非晶-纳米晶混合合金,采用内耗测量方法研究了这种软磁性非晶-纳米晶混合合金的结构变化,并比较了不同处理时间样品的内耗变化,结果表明,经低频脉冲磁场处理后,在92℃附近出现了一个明显的内耗峰,该峰在能量积聚过程中表现出弛豫型内耗的特点,而在降温过程则无转变发生,仅表现出背景内耗的增高.结合正电子寿命谱的观察,分析了样品中缺陷组态的变化规律.实验结果均表明,经低频脉冲磁场较长时间处理后,样品中的亚稳结构与非晶态的亚稳结构明显不同,并具有一定的热稳定性.

The advanced iron base amorphous-nanocrystalline alloys may be obtained by low frequency pulse magnetic field treatment. The internal friction of this soft-magnetic material and the effect of magnetic field treatment duration were studied. There is a peak at about 92 V after low frequency pulse magnetic field treatment, which is related to the energy accumulation process and shows the character of anelasticity internal friction. During temperature down the peak does not appear and only the internal friction background shows obviously increasing. According to the results of positron annihilation lifetime, the change of defects configuration is analyzed. These results show that the metastable structure of material has obviously hot stability, which is different with the initial amorphous mestable structure.