Korean Journal of Materials Research (한국재료학회지)

Materials Research Society of Korea (한국재료학회)
권호 표지
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Fabrication and Structural Observation of a Soft Magnetic Composite Powders by Mechanical Alloying

기계적합금화법에 의한 연자성 복합분말의 제조 및 구조관찰

  • Lee, Chung-Hyo (Department of Advanced Materials Science and Engineering, Mokpo National University)
  • 이충효 (목포대학교 신소재공학과)
  • Received : 2019.03.14
  • Accepted : 2019.04.03
  • Published : 2019.04.27
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Abstract

Fabrication of soft magnetic composite powders for the $Fe_2O_3-Ca$ system by mechanical alloying(MA) has been investigated at room temperature. It is found that soft magnetic composite powders in which CaO is dispersed in ${\alpha}-Fe$ matrix are obtained by MA of $Fe_2O_3$ with Ca for 5 hours. Changes in magnetization and coercivity also reflect the details of the solidstate reduction process of hematite by pure metal of Ca during MA. The saturation magnetization of MA powders increases with increasing MA time and reaches a maximum value of 65 emu/g after 7 hours of MA. The average grain size of ${\alpha}-Fe$ in MA powders, estimated by diffraction line-width, gradually decreases with increasing MA time and reaches 52 nm after 5 hours of MA. It can also be seen that the coercivity of the 5-hour MA sample is fairly high at 190 Oe, suggesting that the grain refinement of already-produced ${\alpha}-Fe$ tends to clearly occur during MA.

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References

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