• Title/Summary/Keyword: $\sigma$-VFe phase

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Phase Analysis of Mechanically Alloyed $\sigma$-VFe Alloy Powders by Neutron and X-ray Diffraction (기계적 합금화한 $\sigma$-VFe합금의 중성자 및 X선 회절에 의한 상분석)

  • 이충효;조재문;이상진;심해섭;이창희
    • Korean Journal of Materials Research
    • /
    • v.11 no.8
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    • pp.664-664
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    • 2001
  • The mechanical alloying (MA) effect in $\sigma$-VFe intermetallic compound was studied by neutron and X-ray diffraction. The structure of MA $\sigma$-VFe powders were characterized by the X- ray diffraction with Cu- $K\alpha$ radiation and neutron diffraction with monochromatic neutrons of $1.835\AA$ using a high resolution powder diffractometer (HRPD). Mechanical alloying of $\sigma$-VFe compound gives rise to a dramatic structural change. After 60 hours of MA, the Fe-Fe distribution of the $\sigma$- phase VFe tetragonal structure with 30 atoms in a unit cell is found to change into that of the $\sigma$-(V,Fe) solid solution with bcc structure, which is a stable phase at elevated temperature above $1200^{\circ}C$. A comparison of X-ray diffraction data for the $\alpha$-phase has been also made with the corresponding neutron diffraction data. The (101) and (111) diffraction peaks of the $\sigma$-phase was clearly observed only in neutron diffraction pattern, which is believed to be a characteristic feature due to the chemical atomic ordering of $\sigma$- VFe phase.

Phase Analysis of Mechanically Alloyed $\sigma$-VFe Alloy Powders by Neutron and X-ray Diffraction (기계적 합금화한 $\sigma$-VFe합금의 중성자 및 X선 회절에 의한 상분석)

  • Lee, Chung-Hyo;Jo, Jae-Mun;Lee, Sang-Jin;Sim, Hae-Seop;Lee, Chang-Hui
    • Korean Journal of Materials Research
    • /
    • v.11 no.8
    • /
    • pp.661-665
    • /
    • 2001
  • The mechanical alloying (MA) effect in $\sigma$-VFe intermetallic compound was studied by neutron and X-ray diffraction. The structure of MA $\sigma$-VFe powders were characterized by the X- ray diffraction with Cu- $K\alpha$ radiation and neutron diffraction with monochromatic neutrons of $1.835\AA$ using a high resolution powder diffractometer (HRPD). Mechanical alloying of $\sigma$-VFe compound gives rise to a dramatic structural change. After 60 hours of MA, the Fe-Fe distribution of the $\sigma$- phase VFe tetragonal structure with 30 atoms in a unit cell is found to change into that of the $\sigma$-(V,Fe) solid solution with bcc structure, which is a stable phase at elevated temperature above $1200^{\circ}C$. A comparison of X-ray diffraction data for the $\alpha$-phase has been also made with the corresponding neutron diffraction data. The (101) and (111) diffraction peaks of the $\sigma$-phase was clearly observed only in neutron diffraction pattern, which is believed to be a characteristic feature due to the chemical atomic ordering of $\sigma$- VFe phase.

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