La-Ca-Sr-Co系高性能干压各向异性永磁铁氧体的研制

以北矿BMS-12预烧料为基料,首先通过湿压工艺确定出适宜的二次添加剂添加量,在此基础上采用干压法制备各向异性永磁铁氧体材料,分析黏合剂、润滑剂用量及磁粉粒度对磁体性能的影响。实验结果表明,樟脑黏合剂和硬脂酸钙润滑剂的适宜添加量分别为0.6wt%、0.8wt%。在0.85~1.00μm的粉料粒度范围内都可以获得较高的剩磁和矫顽力。得到的典型干压磁体性能:Br=421m T,Hcb=296k A/m,Hcj=360k A/m,(BH)max=33.2k J/m3,达到TDK的FB5D性能水平。La-Ca-Sr-Co系干压磁体具有比传统锶永磁铁氧体湿压磁体更高的剩磁和内禀矫顽力。

Development of high performance La-Ca-Sr-Co system dry-press anisotropic permanent ferrite

Based on BMS-12 pre-sintered ferrite powders, suitable amount of additives is determined through the wet-pressing process. On this basis, dry-pressed anisotropic permanent ferrite material was prepared and effects of adhesives, lubricants dosage and powder size on magnetic properties analysized. The experimental results show that, the appropriate amount of camphor adhesive and calcium stearate lubricant is 0.6wt% and 0.8wt%, respectively. High remanence and coercivity can be obtained for particle size of 0.85 to 1.00μm. Dry-pressed magnet ferrite was prepared with typical properities of Br=421mT, Hcb=296kA/m, Hcj=360kA/m, (BH)max=33.2kJ/m3, reaching the level of TDK FB5D. Dry-pressed magnet of La-Ca-Sr-Co system has higher remanence and intrinsic coercivity than traditional wet-pressed Sr-ferrite.