TY - JOUR
T1 - Preparation of Sm−Fe−N bulk magnets with high maximum energy products
AU - Matsunami, R.
AU - Matsuura, M.
AU - Tezuka, N.
AU - Sugimoto, S.
N1 - Funding Information:
This work was partially supported by Toyota Motor Corporation, the Future Pioneering Program “ Development of magnetic material technology for high-efficiency motors” (MgaHEM) commissioned by the New Energy and Industrial Technology Development Organization (NEDO), and the Elements Strategy Initiative Center for Magnetic Materials (ESICMM), Grant number JPMX P 0112101004, through the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan.
Publisher Copyright:
© 2020, Magnetics Society of Japan. All rights reserved.
PY - 2020
Y1 - 2020
N2 - In an effort to increase the maximum energy product ((BH)max) and coercivity (HcJ) of Zn-bonded Sm−Fe−N magnets, we developed a process for preparing Sm−Fe−N and Zn powders with low oxygen contents and subjected them to spark plasma sintering. The oxygen content, remanence, and coercivity of the Sm−Fe−N powder were 0.22 wt%, 151 A·m2·kg−1, and 0.72 MA·m−1, respectively. The oxygen content and secondary average particle size of the Zn powder were 0.083 wt% and 0.93 μm, respectively. The magnetic properties of the Zn-free Sm−Fe−N magnets included an HcJ of 0.86 MA·m−1 and a (BH)max of 188 kJ·m−3, while the Zn-bonded (10 wt%) Sm−Fe−N magnets exhibited excellent magnetic properties with a (BH)max of 200 kJ·m−3 and an HcJ of 1.28 MA·m−1. Compared with previous studies, this is the high (BH)max observed for a Sm−Fe−N bulk magnet simultaneously displaying a high HcJ. The (BH)max of the Zn-bonded magnets was greater than that of the Zn-free magnets owing to the higher relative density of the former. Therefore, Zn is an effective binder for increasing not only the coercivity but also the density of Sm−Fe−N magnets. Consequently, the procedure reported herein permits the successful preparation of high-performance Sm−Fe−N bulk magnets.
AB - In an effort to increase the maximum energy product ((BH)max) and coercivity (HcJ) of Zn-bonded Sm−Fe−N magnets, we developed a process for preparing Sm−Fe−N and Zn powders with low oxygen contents and subjected them to spark plasma sintering. The oxygen content, remanence, and coercivity of the Sm−Fe−N powder were 0.22 wt%, 151 A·m2·kg−1, and 0.72 MA·m−1, respectively. The oxygen content and secondary average particle size of the Zn powder were 0.083 wt% and 0.93 μm, respectively. The magnetic properties of the Zn-free Sm−Fe−N magnets included an HcJ of 0.86 MA·m−1 and a (BH)max of 188 kJ·m−3, while the Zn-bonded (10 wt%) Sm−Fe−N magnets exhibited excellent magnetic properties with a (BH)max of 200 kJ·m−3 and an HcJ of 1.28 MA·m−1. Compared with previous studies, this is the high (BH)max observed for a Sm−Fe−N bulk magnet simultaneously displaying a high HcJ. The (BH)max of the Zn-bonded magnets was greater than that of the Zn-free magnets owing to the higher relative density of the former. Therefore, Zn is an effective binder for increasing not only the coercivity but also the density of Sm−Fe−N magnets. Consequently, the procedure reported herein permits the successful preparation of high-performance Sm−Fe−N bulk magnets.
KW - Fine Zn powder
KW - Low oxygen content
KW - Maximum energy products
KW - Sm−Fe−N magnets
KW - Spark plasma sintering
KW - Zn binder
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U2 - 10.3379/msjmag.2005R003
DO - 10.3379/msjmag.2005R003
M3 - Article
AN - SCOPUS:85084263198
SN - 1882-2932
VL - 44
SP - 64
EP - 69
JO - Journal of the Magnetics Society of Japan
JF - Journal of the Magnetics Society of Japan
IS - 3
ER -