ホーム > 研究活動 > 口頭発表(2018) > High performance Sm-Fe-N Zn-bonded magnets prepared using hydrogen plasma-metalreaction and arc plasma deposition.

研究活動

High performance Sm-Fe-N Zn-bonded magnets prepared using hydrogen plasma-metalreaction and arc plasma deposition.

5th International Conference of Asian Union of Magnetics Societies (IcAUMS2018),June 3-7, 2018 Jeju, Korea

2018年6月4日(月)

Satoshi Sugimoto, Masashi Matsuura, Yuki Nishijima, Nobuki Tezuka, Tomoki Shiraiwa (TohokuUniverisity) ,Noritsugu Sakuma, Tetsuya Shoji (Toyota Motor Corp.)

Abstract

Hydrogen plasma-metal reaction (HPMR) is one of effective methods for preparation of fine particles with low oxygen content. We adopted this method for the improvement of the coercivity of Sm-Fe-N Zn-bonded magnets. The primary and secondary average particle sizes of Zn powders prepared by HPMR were 0.23 and 0.93 ・m, respectively, and the oxygen content was 0.068 wt%. The coercivities of the 15 wt% Zn and 10 wt% Zn Sm-Fe-N Znbonded magnets were 2.66 MAm-1 and 2.41 MAm-1, respectively. High coerecivities were obtained and it is found that the coercivity strongly depended on the oxygen content. Figure 1 shows the temperature dependence of a Sm- Fe-N Zn-bonded magnet prepared using HPMR. The coercivity for the 15 wt% Zn magnet measured at 200 ・C was 1.10 MAm-1, and the temperature coefficient of coercivity was -0.32 %・C-1. Therefore, this Sm-Fe-N Zn-bonded magnet showed high heat resistance. We also adopted arc-plasma deposition (APD) for the preparation Sm-Fe-N powders covered by Zn nanoparticles. Figure 2 shows an SEM microstructure taken from Zn-deposited Sm-Fe-N powders using APD. Zn nanoparticels can be observed on the surface of Sm-Fe-N powders. The Sm-Fe-N Zn-bonded magnet using this powders exhibited higher magnetic properties than those prepared by conventional method. As the Zn distribution was improved in the powders, the Zn content in Zn-bonded Sm-Fe-N magnets could be decreased, which suppressed the decrease in magnetization value. Therefore, it can be said that decreasing particle size and oxygen content in the starting Zn powders improve magnetic properties of Sm-Fe-N Zn-bonded magnets.

その他特記事項

This work was partially supported by the Future Pioneering Program “Development of magnetic material technology for high-efficiency motors” (MagHEM) 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..


研究活動

文部科学省

文部科学省
元素戦略プロジェクト(活動紹介)
NIMS磁石パートナーシップ

元素戦略拠点

触媒・電池元素戦略拠点
触媒・電池元素戦略研究拠点 (京都大学)
東工大元素戦略拠点
東工大元素戦略拠点 (東京工業大学)
構造材料元素戦略研究拠点
構造材料元素戦略研究拠点 (京都大学)
高効率モーター用磁性材料技術研究組合
高効率モーター用 磁性材料技術研究組合