Anisotropic SmCo5 Nanocrystalline Magnet Prepared by Hot Deformation With Bulk Amorphous Precursors

Microstructure and magnetic properties of hot deformed SmCo5 nanocrystalline magnet prepared from amorphous precursors are investigated. Hot pressed magnet as a precursor of the hot deformed magnet is amorphous. After hot deformation process, the SmCo5 magnet with 85% height reduction exhibits CaCu5 crystal structures and the strong c-axis textures. Moreover, the hot deformed SmCo5 magnet bears magnetic properties of H-ci = 31.4 kOe, M-r = 6.42 kG, (BH)(max) = 10.1 MGOe, and the remanence ratio of the magnet is as high as 0.87 due to the strong c-axis textures. In addition, fracture morphology shows that grains of the hot deformed magnet are plate shaped with an average grain size of 200 nm in thickness and 800 nm in diameter. Furthermore, the grain size of the magnet from transmission electron microscopy (TEM) observation has a good agreement with the scanning electron microscopy results. The TEM results also show that a lot of Sm-rich Sm-Co precipitate particles with a size less than 50 nm. These precipitate particles could act as pinning sites leading to high coercivity.