Recent Development of Hot-Pressed-/Deformed Nd–Fe–B Permanent Magnets

In recent years, the applications of rare earth permanent magnetic materials have been expanding, especially in the fields of wind power generation, new energy vehicles and energy-efficient appliances. The scarcity of natural heavy rare earth restricted the broad applications of Nd–Fe–B magnets. Therefore, enhancing the coercivity of the Nd–Fe–B magnets with free or lean heavy rare earth have drawn attention recently. The Nd–Fe–B magnets prepared by hot pressing and hot deformation process possess nanoscale lamellar grains, exhibiting potential to produce the high coercivity magnets without the addition of heavy rare earth elements. The progress in the research on the hot pressing and hot deformation technology for Nd–Fe–B production were summarized. The effect of alloying elements and preparation technologies on the microstructure and properties of hot-deformed magnets was introduced, providing references for preparing high performance Nd–Fe–B magnets by hot pressing and hot deformation process.