机械合金化制备各向同性NdFeB纳米晶磁粉的研究

Preparation of Isotropic NdFeB Magnetic Powder by Mechanical Alloying

在高纯氩气气氛保护下,通过机械合金化技术制备出了纳米晶NdFeB各向同性磁粉。采用X射线衍射分析(XRD)对原料粉的合金化过程及其晶粒尺寸和微观应变进行研究,利用扫描电子显微镜(SEM)和振动样品磁强计(VSM)对制得的纳米晶NdFeB各向同性磁粉的微观形貌及磁学性能进行了研究。结果表明:球磨初始时的冷焊阶段Nd、B原子就已经进入Fe的晶格形成间隙固溶体,随着球磨时间的增加合金粉微观应变增加、平均晶粒度迅速降低,球磨40h后获得的合金粉平均晶粒度达到8nm左右。

Nanocrystalline NdFeB alloy powders were prepared by mechanically milling under inert atmosphere of argon at room temperature.The processing and the effects of alloying process on grain size micro strain of this alloy powders were investigated by X-ray diffraction(XRD).The micro image and magnetic properties of the nanocrystalline powders were investigated by scanning electron microscopy(SEM) and the vibrating sample magnetometer (VSM).The results show that during the cold welding B and Nd atoms have intermingled with the Fe's crystal lattice and come into being the interstitial solid solution.The grain size of the alloy decreases sharply and the micro strain increases with the increasing of the milling time,and the average grain size is about 8 nm after milling 40 hours.