各向异性纳米晶复合稀土磁体的研制

Research and Development of Bulk Anisotropic Nanograin Composite Rare Earth Permanent Magnets

作者成功地开发了全密度各向异性纳米晶复合稀土永磁体,其制备技术新颖,工艺成本低。采用粉末混合技术,纳米磁体的(BH)max可以达到 320～400kJ/m3(40～50MGOe)。而采用粉末镀膜技术,(BH)max可达360～440kJ/m3(45～55MGOe)。这样,制备各向异性纳米晶复合稀土磁体的主要技术困难就得到了克服。此外,作者观察到纳米晶粒复合磁体中软磁相的尺寸可达数十微米。这一尺寸是目前的界面交换耦合模型所建议的软磁相尺寸上限的一千倍以上。继续减小软磁相的尺寸并改善其分布将会进一步改善纳米晶粒复合磁体的磁性能。

Innovative and cost-effective technology for synthesizing bulk anisotropiC nanograin composite rare earth magnets has been developed. Using a powder blending technique, （BH）max of nanograin composite magnets can reach 320 to 400kJ/m^3 （40 to 50 MGOe）, while applying powder coating techniques, （BH）max=360-440 kJ/m^3 （45-55 MGOe） were achieved. Thus, principal technical difficulties in synthesizing bulk anisotropic nanograin composite magnets are successfully overcome. In addition, it was observed that the magnetically soft phase in a composite magnet could be up to tens of micrometers, or more than 1000 times larger than the upper size limit predicted by the current models of interface exchange coupling, which indicates that further reducing the size of the soft phase and improving its distribution will significantly improve the magnetic performance of nanograin composite magnets.