Effect of deformation temperature on crystal texture formation in hot deformed nanocrystalline SmCo5 permanent magnets

Rare earth-cobalt based magnetic materials have attracted considerable attention due to their large anisotropy eld (H_A), high saturation magnetizations (Ms), and high Curie temperatures (T_C). As the first generation of rare earth-transition metal (RE-TM) based permanent magnet, SmCo₅ possesses extraordinary high anisotropy led over 240 kOe, and nanocrystalline SmCo₅ magnet bears coercivity as high as 50 kOe ^[1]. Furthermore, the high T_C and strong corrosion resistance of nanocrystalline SmCo5 magnet make it a promising candidate for practical application at elevated temperature. Hot deformation technique has been considered as one of the effective way to obtain crystallographic texture and thereby magnetic anisotropy in nanocrystalline permanent magnets. Gabay et al observed enhanced (00l) diffraction peak of SmCo₅ phase in the hot deformed Sm₁₇Co₈₃ magnet ^[2], indicating a formation of certain degree of crystallographic texture. Yue et al reported that signi-cantly improved texture can be obtained in the nanocrystalline SmCo₅ alloys subjected to die upsetting at a very high degree of deformation (more than 85% height reduction)^[3]. However, the mechanism of the plastic deformation and texture formation during the hot deformation process is not clear yet. In this paper, the orientation texture of both grains and their boundary planes in the nanocrystalline SmCo₅ anisotropic magnet have been characterized by using the electron backscattered diffraction (EBSD) technique. Based on these results, effect of deformation temperature on the texture and magnetic properties has been discussed.