A high magnetic energy product obtained in hot-deformed Nd-Fe-B magnet by chemical plating Fe-Co bilayer films

• Published in: Journal of alloys and compounds 2024-12, Vol.1008, p.176588, Article 176588
• Main Authors: Ouyang, Yong, Chen, Renjie, Tang, Xu, Yin, Wenzong, Xia, Xianshuang, Cui, Yuhang, Ju, Jinyun, Du, Yeyuan, Yan, Aru
• Format: Article
• Language: English
• Subjects: Chemical plating; Double-layer coating; Nd-Fe-B magnetic powder; Soft magnetic phase
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2024.176588

This study investigates a novel method, chemical plating, with the goal of integrating nano-sized ferromagnetic materials into hot-deformed Nd-Fe-B magnets, potentially enhancing their magnetic properties. Coating Fe-Co double layers on Nd-Fe-B magnetic powder resulted in a significant improvement in the remanence over 10 %, increasing from 1.37 to 1.45 T, as well as an increase in the maximum magnetic energy product from 45.95 to 52.02 MGOe in hot-deformed Nd-Fe-B magnets. Microstructure observations revealed that the coarse non-oriented grains at the interface of powder ribbons were suppressed and the texture of grain alignment in the interior of powder ribbons was enhanced after the coating of Fe-Co. Additionally, there was a noticeable increase in the concentrations of ferromagnetic elements in intergranular phases. The reduced coarse grain regions, the enhanced grain alignment and the increased ferromagnetic intergranular phases are considered to be the main reasons for the enhancement of remanence and maximum magnetic energy product in hot-deformed magnets. [Display omitted] •Fe-Co bilayer film was designed and obtained on the surface of Nd-Fe-B magnetic powder by chemical plating.•Fe-Co coating particles were small (120 to 230 nm in size) and had a uniform distribution.•The oxidation of composite magnetic powder was inhibited by the double-layer coating.•The optimization of fiber microstructure and the increase of ferromagnetic element content in grain boundary phase significantly improve the remanence and maximum magnetic energy product of magnets.