Effect of CaF2 on the Microstructure, Magnetic, and Electrical Properties of Nd–Fe–B Magnets

To increase the electrical resistance of Nd-Fe-B magnets, CaF
₂
were used to fabricate Nd-Fe-B/CaF
₂
composite permanent magnets by hot-pressing and hot-deformation techniques. The influence of CaF
₂
on the microstructures, electrical resistances, and magnetic properties of the Nd-Fe-B/CaF
₂
composite magnets has been investigated. The results show that the cross-sectional microstructure of the composite magnets appeared as layered-structure and wet blending contributed to the formation of smooth CaF
₂
layers. The electrical resistances of the Nd-Fe-B/CaF
₂
composite magnets increased with the amounts of CaF
₂
and reached 1280 μΩ cm in the direction parallel to the pressing direction when the volume of CaF
₂
was 20 vol.%, which increased 456% higher than that of the Nd-Fe-B magnet (230 μΩ cm). But the maximum energy products of the Nd-Fe-B/CaF
₂
composite magnets decreased with the increase of the amounts of CaF
₂
.