中国物理B ›› 2011, Vol. 20 ›› Issue (12): 127502-127502.doi: 10.1088/1674-1056/20/12/127502

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Relation between oxidation microstructure and the maximum energy product loss of a Sm2Co17 magnet oxidized at 500 ℃

刘丽丽, 蒋成保   

  1. Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191, China
  • 收稿日期:2011-06-22 修回日期:2011-07-22 出版日期:2011-12-15 发布日期:2011-12-15
  • 基金资助:
    Project supported by the National High Technology Research and Development Program of China (Grant No. 2010AA03A401), the National Natural Science Foundation of China (Grant No. 51071010), the Aviation Foundation of China (AFC) (Grant No. 2009ZF51063), and the Fundamental Research Funds for the Central Universities.

Relation between oxidation microstructure and the maximum energy product loss of a Sm2Co17 magnet oxidized at 500 ℃

Liu Li-Li(刘丽丽) and Jiang Cheng-Bao(蒋成保)†   

  1. Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191, China
  • Received:2011-06-22 Revised:2011-07-22 Online:2011-12-15 Published:2011-12-15
  • Supported by:
    Project supported by the National High Technology Research and Development Program of China (Grant No. 2010AA03A401), the National Natural Science Foundation of China (Grant No. 51071010), the Aviation Foundation of China (AFC) (Grant No. 2009ZF51063), and the Fundamental Research Funds for the Central Universities.

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摘要： The oxidation microstructure and maximum energy product (BH)max loss of a Sm(Co0.76, Fe0.1, Cu0.1, Zr0.04)7 magnet oxidized at 500 ℃ were systematically investigated. Three different oxidation regions were formed in the oxidized magnet: a continuous external oxide scale, an internal reaction layer, and a diffusion zone. Both room-temperature and high-temperature (BH)max losses exhibited the same parabolic increase with oxidation time. An oxygen diffusion model was proposed to simulate the dependence of (BH)max loss on oxidation time. It is found that the external oxide scale has little effect on the (BH)max loss, and both the internal reaction layer and diffusion zone result in the (BH)max loss. Moreover, the diffusion zone leads to more (BH)max loss than the internal reaction layer. The values of the oxidation rate constant k for internal reaction layer and oxygen diffusion coefficient D for diffusion zone were obtained, which are about 1.91 × 10-10 cm2/s and 6.54 × 10-11 cm2/s, respectively.

Abstract: The oxidation microstructure and maximum energy product (BH)max loss of a Sm(Co0.76, Fe0.1, Cu0.1, Zr0.04)7 magnet oxidized at 500 ℃ were systematically investigated. Three different oxidation regions were formed in the oxidized magnet: a continuous external oxide scale, an internal reaction layer, and a diffusion zone. Both room-temperature and high-temperature (BH)max losses exhibited the same parabolic increase with oxidation time. An oxygen diffusion model was proposed to simulate the dependence of (BH)max loss on oxidation time. It is found that the external oxide scale has little effect on the (BH)max loss, and both the internal reaction layer and diffusion zone result in the (BH)max loss. Moreover, the diffusion zone leads to more (BH)max loss than the internal reaction layer. The values of the oxidation rate constant k for internal reaction layer and oxygen diffusion coefficient D for diffusion zone were obtained, which are about 1.91 × 10-10 cm2/s and 6.54 × 10-11 cm2/s, respectively.

Key words: Sm2Co17 magnet, maximum energy product loss, internal reaction layer, diffusion zone

中图分类号:  (Permanent magnets)

  • 75.50.Ww
75.60.Ej (Magnetization curves, hysteresis, Barkhausen and related effects) 81.65.Mq (Oxidation) 66.30.-h (Diffusion in solids)