氧对Sm(Co,Fe,Cu,Zr)z永磁体性能和显微组织的影响

研究了氧对Sm(Co, Fe, Cu, Zr)z永磁体性能的影响,并借助SEM、EDS和TEM等方法分析了永磁体的显微组织变化,讨论了影响磁体性能的原因.结果表明:在氧含量不高时(质量分数＜0.32%)对磁性能的影响不明显,永磁体具有良好的磁性能;在0.32%～0.4%时,随氧含量的增加磁性能开始下降;氧含量大于0.4%后,磁性能急剧恶化;当大于0.7%后,磁性能基本消失.随着氧含量的增加,磁体的晶粒尺寸减小,以Sm2O3为主的白色析出物增多.非磁性相的增多和有效Sm含量的减少是影响磁性能的主要原因.

Effects of oxygen on the microstructure and magnetic properties of Sm(Co, Fe, Cu, Zr)z permanent magnets

The effects of oxygen on the magnetic properties of Sm (Co, Fe, Cu, Zr)z permanent magnets were studied. SEM, EDS and TEM approaches were used to analyze the microstructure of the permanent magnets. The factors that affect the magnetic properties were discussed. The results indicate that the magnetic properties remain excellent and are not affected when the oxygen content is less than 0.32% in mass fraction. The magnetic properties begin to decrease when the oxygen content is between 0.32% and 0.4%, evidently deteriorate when the oxygen content is above 0.4%, and almost vanish when the oxygen content is more than 0.7%. The particle size of the magnets decreases while more Sm2O3 begins to separate from the magnets gradually. The main factors that affect the magnetic properties are the increase of non-magnetism phase and the decrease of the useful Sm content of the magnets.