VP9-01 Composition Design of Sintered Sm2Co17-type Magnets with High Magnetic Properties and Remanence Temperature Stability
Creators: Long Zan
Zhang Chaoyue
Teng Yuan
Ling Chong
Kang Youning
Zhang
Baoguo
Zhang
Hongguo
Li Yuqing
Yue
Ming
Publisher: name: IEEE
Year: 2025

The Sm2Co17-type permanent magnets exhibit exceptionally high coercivity and excellent temperature stability, thus widespread applications in critical fields such as microwave communication, precision instruments, and high-temperature motors. The advancement in corresponding application fields has imposed greater demands on the temperature stability and magnetic properties. In this study, the composition design were carried out to prepare (Sm,Er)(Co,Fe,Cu,Zr)z magnets with high magnetic properties and remanence temperature stability. Also, the impact of Er substitution for Sm on the magnetic properties and microstructure of 2:17-type magnets and the associated mechanisms were investigated. Experimental results indicate that with increasing Er substitution, the magnetic properties of the magnets gradually decline, accompanied by a significant increase in the remanence temperature coefficient. When the Er substitution reaches 60%, the comprehensive performance is optimal, with remanence of 8.81 kG, coerocvity of 30.01 kOe, while maintaining a near zero temperature coefficient of remanence within the range of 20-150 °C. X-ray diffraction refinement and first-principles calculations reveal that Er initially substitutes for Sm at the 2b crystallographic site in 2:17H phase, thereby increasing the resistance to basal plane slip and atomic diffusion. Consequently, raising the energy barrier for the transformation from the 2:17H phase to the 2:17R phase, resulting in an increase in the 2:17H phase content. TEM results disclose that as the Er substitution increases, the cellular structure morphology was gradually deteriorated, and the Cu-enrichment and continuity of the 1:5 phase was weakened, and ordering-degree of intracellular phase also decreased, thereby reducing the coercivity. Our findings can provide reliable references for the development of SmCo magnets with high remanence temperature stability.
The Sm2Co17-type permanent magnets exhibit exceptionally high coercivity and excellent temperature stability, thus widespread applications in critical fields such as microwave communication, precision instruments, and high-temperature motors. The advancement in corresponding application fields has imposed greater demands on the temperature stability and magnetic properties. In this study, the composition design were carried out to prepare (Sm,Er)(Co,Fe,Cu,Zr)z magnets with high magnetic properties and remanence temperature stability. Also, the impact of Er substitution for Sm on the magnetic properties and microstructure of 2:17-type magnets and the associated mechanisms were investigated. Experimental results indicate that with increasing Er substitution, the magnetic properties of the magnets gradually decline, accompanied by a significant increase in the remanence temperature coefficient. When the Er substitution reaches 60%, the comprehensive performance is optimal, with remanence of 8.81 kG, coerocvity of 30.01 kOe, while maintaining a near zero temperature coefficient of remanence within the range of 20-150 °C. X-ray diffraction refinement and first-principles calculations reveal that Er initially substitutes for Sm at the 2b crystallographic site in 2:17H phase, thereby increasing the resistance to basal plane slip and atomic diffusion. Consequently, raising the energy barrier for the transformation from the 2:17H phase to the 2:17R phase, resulting in an increase in the 2:17H phase content. TEM results disclose that as the Er substitution increases, the cellular structure morphology was gradually deteriorated, and the Cu-enrichment and continuity of the 1:5 phase was weakened, and ordering-degree of intracellular phase also decreased, thereby reducing the coercivity. Our findings can provide reliable references for the development of SmCo magnets with high remanence temperature stability.