烧结Nd-Fe-B磁体在电机应用中的力学分析

Analysis of Mechanical Properties of Sintered Nd-Fe-B Magnets for Electric Motor Applications

研究了烧结Nd-Fe-B磁体沿平行和垂直取向方向的抗弯强度、断裂韧度以及微观结构,发现其力学性能沿不同取向方向存在较大差异。探讨了烧结Nd-Fe-B磁体力学各向异性的起因,分析表明:烧结Nd-Fe-B磁体力学各向异性来源于结晶过程中晶粒生长的各向异性,从而产生了富Nd相相对于主相的择优分布。由于磁粉因磁场取向使这种择优分布得以保留,进而产生了烧结Nd-Fe-B磁体力学强度各向异性。

This study descries the flexural strength, fracture toughness and microstructures of Nd-Fe-B sintered magnets in the directions of parallel and perpendicular with magnetization orientation. It is found that the mechanical properties greatly depend on crystal orientation due to the grain growth in anisotropy during sintering process, resulting in a preferred distribution of the Nd-rich phase in sintered samples. That distribution of the Nd-rich phase in the intergranular region was obtained from the magnetic alignment process. Therefore, the sintered Nd-Fe-B magnets exhibit the anisotropic mechanical properties.