Preparation of Isotropic NdFeB Magnetic Powder by Mechanical Alloying

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.