利用共伴生混合稀土制备RE-Fe-B永磁材料

Magnetic Properties and Microstructure of Re-Fe-B Permanent Magnet Prepared Using Mixed Rare Earth of Bayan Obo

摘要:

利用白云鄂博共伴生混合稀土（MM）制备了成分为(PrNd)14-xMMxFe80.4B5.6的稀土永磁材料，MM替代30%PrNd合金，磁体磁能积为238.08 kJ/m3，剩磁为1.18 T，矫顽力726.75 kA/m，发现La、Ce元素以氧化物的形式分布在富稀土相中，主相中存在（NdCe）2Fe14B固溶体，相比单独添加La、Ce的磁体，获得相同的磁性能时，(PrNd)14-xMMxFe80.4B5.6磁体的La含量较高，磁体中混合稀土La、Ce、Pr、Nd的协同作用促进了MM的高效利用。利用高场动态磁畴显微镜观察了磁体的畴结构动态变化，磁体内部出现大量的穿晶畴，穿晶畴的畴壁可穿过晶界，磁化过程中磁畴扩展容易。

Abstract:

(PrNd)14-xMMxFe80.4B5.6 permanent magnet materials were prepared from mixed rare earth (MM) of Bayan obo. 30% of PrNd alloy was replaced by MM. The material exhibits a remanence of 1.18 T, a maximum energy product 238.08 kJ/m3, and an intrinsic coercivity of remanence 726.75 kA/m. Oxide of La and Ce exists in rich rare earth phase and there are (NdCe)2Fe14B and (NdLa)2Fe14B in main phase. Compared with others magnets, La content in (PrNd)14-xMMxFe80.4B5.6 magnet is higher when getting the similar magnetic performance. La, Ce, Pr and Nd in the mixed rare earth magnet act together, so MM is used efficiently. Domain structure change was observed by high field Kerr microscopy. The domain wall could be through the grain boundary, and the magnetic domain is easy to spread under magnetic field.