Effect of Nd-Co on microstructure and magnetic properties of Nd-Ce-Y-Fe-B sintered magnets

• Published in: Results in physics 2022-09, Vol.40, p.105829, Article 105829
• Main Authors: Jia, Zhi, Kou, Mingpeng, Cao, Shuai, Yang, Xintong, Ding, Guangfei, Guo, Shuai, Fan, Xiaodong, Zheng, Bo, Chen, Renjie, Yan, Aru
• Format: Article
• Language: English
• Subjects: Magnetic properties; Microstructure; Nd-Ce-Y-Fe-B sintered magnets; Nd-Co alloy
• ISSN: 2211-3797; 2211-3797
• DOI: 10.1016/j.rinp.2022.105829

•Adding NdCo2 makes the magnet remanence and coercivity increase at the same time.•The addition of NdCo2 greatly increases the Curie temperature of the magnet from 573.00 K to 613.35 K, an increase of 7 %.•This work provides new insights into the development of high-abundance rare earth permanent magnets. The magnetic properties and microstructure of Nd-Ce-Y-Fe-B magnets with Nd-Co boundary additions (0, 1, 3, and 5 wt%) have been systematically investigated. The coercivity, remanence, and Curie temperature of the magnets showed to be all simultaneously improved with appropriate Nd-Co addition, especially, a significant coercivity increase of 15% accompanied with the remanence optimization was obtained at 3 wt% Nd-Co addition. The analyses revealed that the coercivity enhancement was attributed to the widened grain boundary width and the reduced magnetic exchange coupling between grains by the Nd-Co intergranular introduction. By designing the partial substitution, e.g. Co for Fe and Nd for Ce in matrix phase grains, the remanence improvement was achieved with the increased net magnetic moment, compensating the magnetic dilution brought by the extra alloy additions. Meanwhile, the Curie temperature of the magnet was improved with the weakened negative interaction. The combined intrinsic and microstructural modification in this study provides new insights into the preparation of high-abundance magnets with high coercivity, high remanence, and excellent temperature stability.