TY - JOUR
T1 - Increase of energy products of Zn-bonded Sm-Fe-N magnets with low oxygen content
AU - Matsuura, Masashi
AU - Nishijima, Yuki
AU - Tezuka, Nobuki
AU - Sugimoto, Satoshi
AU - Shoji, Tetsuya
AU - Sakuma, Noritsugu
N1 - Funding Information:
This work was partially supported by the Future Pioneering Program “Development of magnetic material technology for high-efficiency motors” commissioned by the New Energy and Industrial Technology Development Organization (NEDO), the Elements Strategy Initiative Center for Magnetic Materials (ESICMM) under the outsourcing project of MEXT and Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number 16K144310 .
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/12/1
Y1 - 2018/12/1
N2 - 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.
AB - 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.
KW - Arc plasma deposition
KW - Binder less
KW - Maximum energy products
KW - Oxygen content
KW - Sm-Fe-N magnets
KW - Spark plasma sintering
KW - Zn binder
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U2 - 10.1016/j.jmmm.2018.07.064
DO - 10.1016/j.jmmm.2018.07.064
M3 - Article
AN - SCOPUS:85050354371
VL - 467
SP - 64
EP - 68
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
SN - 0304-8853
ER -