稀土永磁材料绝缘特性研究

稀土永磁材料具有金属基的导电性,因高频交变场环境下磁体内出现涡流效应而降低磁性能,难以稳定正常工作,尤其是无法应用在高转速电机领域.本文对磁体内涡流的分布特征进行了分析,揭示了稀土永磁合金微晶结构分布对磁体绝缘特性的影响.并从宏观角度通过对磁粉的绝缘包覆以及复合粉粒夹杂截流的方案设计,找到制备具有优良电绝缘特性、高性能复合稀土永磁体的有效途径.

Research on the Electrical Insulation of Rare Earth Permanent Magnetic Materials

Rare earth permanent magnetic material is a kind of electrical conductor, and its magnetic properties degrades because of eddy current. As a result, the magnet can not operate stably in high frequency AC field,especially in electromotors with high speed. In the present work, the distribution feature of eddy current in RE magnets were analyzed. As far as rare earth permanent magnets concerned, for the first time, the relationship between the insulation feature and microstructure was revealed. A process scheme was proposed to prepare rare earth permanent magnets with electrical insulation and high magnetic performance. It mainly utilized both macromolecules as insulating folium to surround tiny rare earth permanent magnetic powders and insulating magnetic powder of ferrite as compound insulating component to obstruct eddy current.