The mechanical properties of Sintered NdFeB magnets:

　　In recent years, functional material is developed towards the direction of the integration of structure and function, mechanics performance and strengthening and toughening research of permanent magnets materials began to attract attention.

　　A large number of experiments show that: the fracture mode of sintered NdFeB magnets is intergranular crack, the flexural strength and fracture toughness in the parallel and perpendicular direction and orientation have strong anisotropy. In the process of sintering, the existing strong shrinkage anisotropy is anisotropic reasons to result in fracture behavior of sintered Nd FeB magnets materials.

　　By changing the tempering process, controling rare earth phase distribution and proper adjustment of the content of B, can improve the bending strength of sintered Nd-Fe-B greatly, without reducing the magnetic properties. High strength and toughness of NdFeB magnets are developed, the impact overload performance is more than 10, strength is more than 400Pa, when Na content is lower than 19, the sintered Nd - Fe-B impact resistance with increasing the mass fraction of Na increased obviously, when the mass fraction of Na is higher than 19, the mass fraction of Na is further increased, the fracture toughness of magnet has no significant increase.

　　Light rare earth element Pr replaced the impact properties of sintered Ce-Fe-B, heavy rare earth element Dy replaced the impact properties of sintered Re-Fe-B.