{"title":"通过 Dy70Al10Cu20 晶界扩散提高 Nd-Fe-Co-B 磁体的矫顽力并优化其微观结构","authors":"Jing Liu , Jiateng Zhang , Jiyuan Xu , Yanqiu Xiong , Ruiyang Meng , Shengzhi Dong","doi":"10.1016/j.intermet.2024.108325","DOIUrl":null,"url":null,"abstract":"<div><p>The effect of grain boundary diffusion on the magnetic properties and microstructure of Nd-Fe-Co-B sintered magnets is investigated using Dy<sub>70</sub>Al<sub>10</sub>Cu<sub>20</sub> alloy as the diffusion source. After the secondary annealing of the Nd-Fe-Co-B sintered magnet (<em>H</em><sub><em>cj</em></sub> = 7.94 kOe), its coercivity is substantially increased to 13.10 kOe. Following post-diffusion annealing, the coercivity of the sintered magnet significantly increased to 20.86 kOe. Microstructure analysis revealed that after the second annealing, the main phase grains in the magnet were connected but lacked thin intergranular phases. The distribution of Co was uneven, with an abundance of soft magnetic phases rich in Co, which was not conducive to improving coercivity. After diffusion, Dy formed a shell structure with high magnetic crystal anisotropy on the outer side of the main phase grains, leading to a significant increase in coercivity. Al and Cu entered the interior of the magnet, reducing the melting point of the grain boundary phase and promoting the uniform distribution of Co through the flow of the liquid phase. A large amount of thin continuous intergranular phase is generated inside the magnet, which helps reduce the exchange coupling between hard magnetic grains. The experimental results indicate that the Dy-Al-Cu alloy can effectively enhance the grain boundary structure of Nd-Fe-Co-B magnets, reduce the abundance of Co-rich phases, and improve the coercivity of the magnet.</p></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":null,"pages":null},"PeriodicalIF":4.3000,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Coercivity enhancement and microstructure optimization of Nd-Fe-Co-B magnets by Dy70Al10Cu20 grain boundary diffusion\",\"authors\":\"Jing Liu , Jiateng Zhang , Jiyuan Xu , Yanqiu Xiong , Ruiyang Meng , Shengzhi Dong\",\"doi\":\"10.1016/j.intermet.2024.108325\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The effect of grain boundary diffusion on the magnetic properties and microstructure of Nd-Fe-Co-B sintered magnets is investigated using Dy<sub>70</sub>Al<sub>10</sub>Cu<sub>20</sub> alloy as the diffusion source. After the secondary annealing of the Nd-Fe-Co-B sintered magnet (<em>H</em><sub><em>cj</em></sub> = 7.94 kOe), its coercivity is substantially increased to 13.10 kOe. Following post-diffusion annealing, the coercivity of the sintered magnet significantly increased to 20.86 kOe. Microstructure analysis revealed that after the second annealing, the main phase grains in the magnet were connected but lacked thin intergranular phases. The distribution of Co was uneven, with an abundance of soft magnetic phases rich in Co, which was not conducive to improving coercivity. After diffusion, Dy formed a shell structure with high magnetic crystal anisotropy on the outer side of the main phase grains, leading to a significant increase in coercivity. Al and Cu entered the interior of the magnet, reducing the melting point of the grain boundary phase and promoting the uniform distribution of Co through the flow of the liquid phase. A large amount of thin continuous intergranular phase is generated inside the magnet, which helps reduce the exchange coupling between hard magnetic grains. The experimental results indicate that the Dy-Al-Cu alloy can effectively enhance the grain boundary structure of Nd-Fe-Co-B magnets, reduce the abundance of Co-rich phases, and improve the coercivity of the magnet.</p></div>\",\"PeriodicalId\":331,\"journal\":{\"name\":\"Intermetallics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.3000,\"publicationDate\":\"2024-05-06\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Intermetallics\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0966979524001444\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Intermetallics","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0966979524001444","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
摘要
以 Dy70Al10Cu20 合金为扩散源,研究了晶界扩散对钕铁硼烧结磁体的磁性能和微观结构的影响。Nd-Fe-Co-B 烧结磁体(Hcj = 7.94 kOe)经过二次退火后,其矫顽力大幅提高到 13.10 kOe。后扩散退火后,烧结磁体的矫顽力大幅提高到 20.86 kOe。显微结构分析表明,第二次退火后,磁体中的主相晶粒相连,但缺乏薄的晶间相。Co 的分布不均匀,富含 Co 的软磁相较多,不利于提高矫顽力。扩散后,Dy 在主相晶粒外侧形成了具有高磁晶体各向异性的壳结构,从而显著提高了矫顽力。Al 和 Cu 进入磁体内部,降低了晶界相的熔点,并通过液相流动促进了 Co 的均匀分布。磁体内部产生了大量薄的连续晶间相,有助于降低硬磁性晶粒之间的交换耦合。实验结果表明,Dy-Al-Cu 合金能有效增强钕铁硼磁体的晶界结构,降低富 Co 相的丰度,提高磁体的矫顽力。
Coercivity enhancement and microstructure optimization of Nd-Fe-Co-B magnets by Dy70Al10Cu20 grain boundary diffusion
The effect of grain boundary diffusion on the magnetic properties and microstructure of Nd-Fe-Co-B sintered magnets is investigated using Dy70Al10Cu20 alloy as the diffusion source. After the secondary annealing of the Nd-Fe-Co-B sintered magnet (Hcj = 7.94 kOe), its coercivity is substantially increased to 13.10 kOe. Following post-diffusion annealing, the coercivity of the sintered magnet significantly increased to 20.86 kOe. Microstructure analysis revealed that after the second annealing, the main phase grains in the magnet were connected but lacked thin intergranular phases. The distribution of Co was uneven, with an abundance of soft magnetic phases rich in Co, which was not conducive to improving coercivity. After diffusion, Dy formed a shell structure with high magnetic crystal anisotropy on the outer side of the main phase grains, leading to a significant increase in coercivity. Al and Cu entered the interior of the magnet, reducing the melting point of the grain boundary phase and promoting the uniform distribution of Co through the flow of the liquid phase. A large amount of thin continuous intergranular phase is generated inside the magnet, which helps reduce the exchange coupling between hard magnetic grains. The experimental results indicate that the Dy-Al-Cu alloy can effectively enhance the grain boundary structure of Nd-Fe-Co-B magnets, reduce the abundance of Co-rich phases, and improve the coercivity of the magnet.
期刊介绍:
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