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Microstructures and coercivity mechanism of 2:17-type Sm-Co magnets with high remanence

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Abstract

Sm(CobalFe0.245Cu0.07Zr0.02)7.8 (at%) sintered magnets with high remanence (Br ~1.15 T) were prepared using a traditional powder metallurgy method. Tunable magnetic properties, especially intrinsic coercivity (H cj), were obtained through adjusting isothermal procedure parameters. H cj of the magnets increases from 305 to 752 kA · m−1 with isothermal annealing time increasing from 3 to 20 h, while B r of the magnets almost keeps constant. From the bright field transmission electron microscopy (TEM) images, it is found that: (1) there is dispersed precipitated phase with very small size in the magnet annealed for 3 h, while the magnets annealed for 20 h have distinct and intact cellular structure; (2) the number density of Z-phase in magnet annealed for 20 h is bigger than that for 3 h. Besides, the finer microstructures were studied with high-resolution transmission electron microscopy (HRTEM).

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Acknowledgments

This study was financially supported by the National Basic Research Program of China (No. 2014CB643701) and the National Natural Science Foundation of China (No. 51171048).

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Authors and Affiliations

  1. Division of Functional Materials, Central Iron and Steel Research Institute, Bei**g, 100081, China

    Wei Sun, Ming-Gang Zhu, Yi-Kun Fang, Zhi-Ying Liu, Zhao-Hui Guo & Wei Li

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  1. Wei Sun
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  2. Ming-Gang Zhu
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  3. Yi-Kun Fang
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  4. Zhi-Ying Liu
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  5. Zhao-Hui Guo
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Correspondence to Ming-Gang Zhu.

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Sun, W., Zhu, MG., Fang, YK. et al. Microstructures and coercivity mechanism of 2:17-type Sm-Co magnets with high remanence. Rare Met. 41, 1353–1356 (2022). https://doi.org/10.1007/s12598-015-0513-6

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  • DOI: https://doi.org/10.1007/s12598-015-0513-6

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