铸锭组织的不均匀性对烧结Nd-Fe-B磁体的制粉工艺及磁性能的影响

Influence of the Inhomogenous Microstructures of Nd-Fe-B Ingot on the Powdering Process of Sintered Magnets and Their Magnetic Properties

研究了NdFeB铸锭中显微组织的分布情况,观察到铸锭中Nd2Fe14B相、富Nd相以及αFe等显微组织的不均匀分布所造成的铸锭的不同部位的脆性不一样,使得在随后的气流磨制粉过程中磁粉不能以均匀的成分制出,导致烧结NdFeB磁体磁性能的严重不一致。

The distribution of microstructures of Nd Fe B ingot has been studied.It is observed that the distribution of microstructures such as Nd 2Fe 14 B,α Fe as well as Nd riched phase in bulk ingot is inhomogenous.Such an inhomogeneity results in an inhomogenous fragility throughout the whole ingot,and the powders prepared by jet milling can not be ejected out in a homogenous composition,therefore,the magnetic properties of the sintered magnets prepared by these powders show a large fluctuation.