Research Progress on Mechanical Property Improving Methods and MachiningMethods for Rare Earth Permanent Magnetic Materials

Rare earth permanent magnetic materials are widely used in traditional industries, wind power generation and new energy vehicles because of their excellent magnetic properties. However, due to the brittleness of intermetallic compounds, the mechanical properties and machinability of rare earth permanent magnetic materials are poor, which limit their application. The reasons for poor ductility and toughness along with the fracture mechanisms of rare earth permanent magnetic materials are summarized. The methods of improving their mechanical properties in recent years are reviewed, including the optimization of grain size and distribution, the improvement of strength and ductility of the matrix phase, the improvement of strength and ductility of the grain boundary, and the reduction of mechanical property anisotropy. The machining methods of rare earth permanent magnetic materials are described. Finally, a brief prospect for the future development directions of this field is provided.