Preparation of Nanocrystalline Nickel Powders by High Energy Ball Milling

The structure, morphology and phase change of nanocrystalline nickel powders prepared by high energy ball milling were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results indicate that the average particle size and grain size of the nickel powders decrease and the strain of the powders increases with the increasing milling time. The flake nickel powders with grain size of 17 nm which are polycrystalline structure were obtained after 54 h milling, and the particle size is in the range of 150 to 200 nm, the strain of the particle is 0.48%. When the milling time is 98 h, amorphous phase appears, but the majority is still polycrystalline phase, the grain size and strain are 7 nm and 1.24% respectively, the powders has severe agglomeration.