Abstract
To increase the maximum energy product, (BH)max, of Zn-bonded Sm-Fe-N magnets, a process for preparing a Sm-Fe-N powder with a low oxygen content was developed. The Sm-Fe-N powder containing 0.23 wt% oxygen was prepared by ball milling and nitriding, and the powder remanence and coercivity were 140 A·m2kg−1 and 0.72 MA·m−1, respectively. Arc plasma deposition (APD) was used for Zn addition. Fine Zn particles several tens of nanometers in size were deposited on the Sm-Fe-N powder under vacuum conditions, and APD prevented the oxygen content increasing in the Zn-deposited Sm-Fe-N powder. The low-oxygen Sm-Fe-N powder was pressed and sintered by spark plasma sintering (SPS), and 3.3 wt% Zn-bonded and Zn-free Sm-Fe-N magnets were prepared. For both Zn-bonded and Zn-free Sm-Fe-N magnets, the density increased with increasing sintering pressure, and the relative density of the Zn-bonded Sm-Fe-N magnet was 89% and that of the Zn-free Sm-Fe-N magnet was 85% after SPS. The coercivities of the Zn-bonded and Zn-free Sm-Fe-N magnets were both high at 1.1 and 0.8 MA·m−1, respectively. (BH)max of these magnets increased with increasing relative density, and the highest (BH)max value of the Zn-bonded Sm-Fe-N magnets was 153 kJ·m−3 and that of the Zn-free Sm-Fe-N magnet was 179 kJ·m−3.
Original language | English |
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Pages (from-to) | 64-68 |
Number of pages | 5 |
Journal | Journal of Magnetism and Magnetic Materials |
Volume | 467 |
DOIs | |
Publication status | Published - 2018 Dec 1 |
Keywords
- Arc plasma deposition
- Binder less
- Maximum energy products
- Oxygen content
- Sm-Fe-N magnets
- Spark plasma sintering
- Zn binder
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics