Rare earth Nd-Fe-B, a widely used magnet composition, was synthesized in a shape of powders using gas atomization, a rapid solidification based process. The microstructure and properties were investigated in accordance with solidification rate and densification. Detailed microstructural characterization was performed by using scanning electron microscope (SEM) and the structural properties were measured by using X-ray diffraction. Iron in the form of α-Fe phase was observed in powder of about 30 μm. It was expected that fraction of Nd2Fe14B phase increased rapidly with decrease in powder size, on the other hand that of α-Fe phase was decreased. Nd-rich phase diffused from grain boundary to particle boundary after hot deformation due to capillary action. The coercivity of the alloy decreased with increase in powder size. After hot deformation, Nd2Fe14B phase tend to align to c-axis.

NdFeB anisotropic sintered permanent magnets are typically fabricated by strip casting or melt spinning. In this study, the plastic deformability of an NdFeB alloy was investigated to study the possibility of fabricating anisotropic sintered magnets using gas atomized powders. The results show that the stoichiometric composition Nd12Fe82B6 softens at high temperatures. The aspect ratio and orientation factor of Nd12Fe82B6 billets after plastic deformation were found to increase with increasing plastic deformation temperature, particularly above 800℃. This confirms that softening at high temperatures can lead to plastic deformation of Nd2Fe14B hard magnetic phases.