• Title/Summary/Keyword: 급속 응고

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Effect of quenching rate and crystallization behavior on the magnetic properties of annealed Nd-Fe-B ribbons (Melt-spun Nd-Fe-B 리본의 자기적 특성에 미치는 급속응고속도 및 결정화 거동의 영향)

  • 이경섭;서수정
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.8 no.4
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    • pp.655-659
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    • 1998

  • The effect of quenching speed of melt-spinning on intrinsic coercivity ($_iH_c$$) of annealed ribbons and the crystallization behavior from amorphous $Nd_{14.73}Fe_{78.67}B_{6.60}$ alloy have been studied. We have found that the intrinsic coecivity for annealed melt-spun ribbon is reduced with increasing of quenching rate. $\alpha$-Fe and $Fe_3B$ were formed as intermediate phases prior to the formation of $Nd_2Fe_{14}B$ phase during crystallization. The $Fe_3B$ is disappeared with crystallization of $Nd_2Fe_{14}B$ phase. But the $\alpha$-Fe phase is retained in fully crystallized ribbon by annealing. The intrinsic coercivity loss of annealed ribbon with increasing of quenching speed is believed to be due to existence of soft magnetic phase $\alpha$-Fe in annealed ribbons.

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Magnetic Propwrties of High Quality $Nd_{12}Fe_{80}B_{6}(Nb, M)$ (M=Ti/Cu/Ga) Melt-Spun Ribbons (고특성 $Nd_{12}Fe_{80}B_{6}(Nb, M)$ (M=Ti/Cu/Ga)급속응고리본의 자기특성)

  • 김윤배;김창석;김동환;이갑호;김택기
    • Journal of the Korean Magnetics Society
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    • v.2 no.1
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    • pp.44-49
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    • 1992

  • Magnetic properties and microstructures of $Nd_{12}Fe_{80}B_{6}(Nb,\;M)$ (M=Ti/Cu/Ga) melt-spun ribbons prepared by single wheel technique have been studied. The results of microstructural study have shown that Ga is effective for the orientation of c-axis normal to the ribbon plane. The Ga-added melt-spun ribbon, $Nd_{12}Fe_{80}B_{6}(Nb,\;Ga)$, quenched at $V_{s}=17.9\;m/s$ was mostly composed of fine grains of about 30 nm in size with the textured free-side surface. The powder of this ribbon aligned in mag-netic field showd a high remanence of 0.87 T which was about 5 % higher than that of ribbon itself. It is believed that there is a possibility to fabricate a new type of HIREM melt-spun ribbon with highly textured free-side surface.

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