大块非晶Nd60Fe20Co10Al10合金在晶化过程中磁粘滞行为的研究

Study on the Magnetic Viscosity of Nd60Fe20Co10Al10 Bulk Amorphous Alloy during Crystallization Process

摘要:

本文通过铜模吸铸法制备出了Nd60Fe20Co10Al10大块非晶合金，研究了该合金在晶化过程中的结构与磁性能，并利用等待时间法研究了其在晶化过程中的磁粘滞行为，结果表明：在453 K~783 K温度退火时，合金的磁性能变化不大。当退火温度高于783 K时，合金的剩余磁化强度（Mr）、饱和磁化强度（Ms）和矫顽力（iHc）的值均急剧降低，在803 K退火后，合金完全晶化，铁磁性消失。当合金在703 K和753 K退火后，合金的激活体积Va和激活直径Da的数值变化不大，而合金的扰动场Hf则呈现先上升后下降的现象，并且在703 K时达到最大值，这是因为703 K样品中存在的亚稳相造成了扰动场的增加。此外，本文还讨论了这些微观磁性参数与合金宏观磁性能的关联性。

Abstract:

The Nd60Fe20Co10Al10 bulk amorphous alloy was prepared by suction casting into the copper mould. The microstructure and magnetic property of the alloy during crystallization process were studied. The magnetic viscosity of this alloy during crystallization process was investigated by waiting time method. It was found that magnetic properties of the Nd60Fe20Co10Al10 bulk amorphous alloys annealed at temperature below 783 K had a slight change. However, after annealing at temperature higher than 783 K, values of the remanence (Mr), saturation magnetization (Ms) and intrinsic coercivity (iHc) decreased significantly. Furthermore, the alloy showed paramagnetic behavior after annealing at 803 K. When samples were annealed at 703 K and 753 K, the activation volume (Va) and activation diameter (Da) changed slightly, while the fluctuation field (Hf) showed a maximum at 703 K. It was due to the presence of a metastable phase. The relationship of parameters of magnetic viscosity and magnetic property of the Nd60Fe20Co10Al10 alloy was discussed.