高丰度钇在永磁材料中的应用研究

Application of High Abundance Yttrium in Permanent Magnetic Materials

促进高丰度元素在稀土永磁材料中的应用是推动中国稀土资源平衡利用的重要举措,目前针对高丰度La, Ce磁体的研究已经取得一定的进展,而高丰度Y元素在永磁材料中的研究相对不足。获得稳定的物相结构和理想的微观组织结构是发展低成本高性能稀土永磁材料的关键。本课题组的研究表明:通过小原子半径的Y元素取代,能够稳定形成主相的四方结构,同时避免晶界杂相的生产;Y元素较强的主相形成能力能够促进Y取代磁体中天然的核壳组织结构的形成,进一步通过Y/Ce的共同取代,能够实现对高丰度元素在磁体内分布行为的调控;通过设计富稀土含镓的合金成分,在15%Y(原子分数)取代Nd的条件下获得1.72 T的室温矫顽力,同时磁体具有较好的矫顽力热稳定性,与商业的含Dy磁体相当。

Promoting the application of high-abundance rare earth elements in permanent magnetic materials is an effective approach to balance the utilization of rare earth resources. At present, the research at high-abundance Y elements is relatively insufficient. Obtaining a stable phase structure and ideal microstructure is the key to the development of low-cost high-performance rare earth permanent magnet materials. Our research shows that Y can form the 2∶14∶1 tetragonal structure, while avoiding the production of grain boundary miscellaneous phases. The strong main phase forming ability of the Y element can promote the formation of core-shell structure. Further through the co-substitution of Y/Ce, the distribution of high-abundance elements in the magnet can be regulated. In the Y-substituted alloy composition with rare earth-rich and gallium-doped, the room temperature coercive force of 1.72 T is obtained in 15%Y(atom fraction) substituted magnet. The thermal stability of coercivity is excellent, which is equivalent to the commercial Dy-containing magnet.