Journal of Powder Materials (한국분말재료학회지)

The Korean Powder Metallurgy & Materials Institute (한국분말재료학회 (*구 분말야금학회))
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Microstructure Control and Magnetic Property of Nd-Fe-B Sintered Magnets After Cyclic Heat Treatment

반복 열처리한 Nd-Fe-B 소결 자석의 미세구조 제어 및 자성특성 평가

  • Kim, Se-Hoon (Division of Materials Science and Engineering, Hanyang University) ;
  • Kim, Hoon-Sup (Division of Materials Science and Engineering, Hanyang University) ;
  • Kim, Dong-Hwan (Korea Institute of Materials Science) ;
  • Kim, Young-Do (Division of Materials Science and Engineering, Hanyang University)
  • 김세훈 (한양대학교 신소재공학과) ;
  • 김훈섭 (한양대학교 신소재공학과) ;
  • 김동환 (한국기계연구원부설 재료연구소) ;
  • 김영도 (한양대학교 신소재공학과)
  • Published : 2008.12.28
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Abstract

Sintered Nd-Fe-B magnets have been widely used due to their excellent magnetic properties, especially for driving motors of hybrid and electric vehicles. The microstructure of Nd-Fe-B magnets strongly affects their magnetic properties, in particular the coercivity. Therefore, a post-sintering process like heat-treatment is required for improving the magnetic properties of Nd-Fe-B sintered magnets. In this study, cyclic heat treatment was performed at temperatures between $350^{\circ}C$ and $450^{\circ}C$ up to 16 cycles in order to control microstructures such as size and shape of the Nd-rich phase without grain growth of the $Nd_{2}Fe_{14}B$ phase. The 2 cycles specimen at this temperature range showed more homogeneous microstructure which leads to higher coercivity of 35 kOe than as-sintered one.

Keywords

References

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