Effects of Ga Addition on the Formability of Main Phase and Microstructure of Hot-Deformed Ce–Fe–B Magnets

Abstract

The powders of Ce29.82Fe69.18B1.0 (CeFeB) and Ce29.82Fe68.65Ga0.53B1.0 (CeFeGaB) (wt%) were prepared by melt spinning. Microstructure and phase composition of the prepared powders were characterized by X-ray diffraction (XRD) and Mossbauer spectrometry. The results indicated that the as-spun ribbons comprised multi-phases, including CeFe17, Ce-rich phase, $\alpha $ -Fe phase, and continuous phase. The proportion of the main phase (Ce2Fe14B) in the CeFeGaB ribbons increased as a result of Ga addition. Then, the bulk samples were produced by hot pressing at 700 °C followed by hot deformation (HD) at 800 °C with a height reduction of 75%, and then investigated by field emission scanning electron microscope, high resolution transmission electron microscope, XRD, and vibrating sample magnetometer. The investigation showed a strong crystallographic texture in the HD CeFeGaB magnet and a weak magnetic anisotropy in the HD CeFeB magnet, which could be attributed to the Ga addition that modified the microstructure of grain boundary and the distribution of the Ce–Ga-rich phase.