• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1000-1001
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• 2006

Two atomized alloy powders were pre-compacted by cold and subsequently hot forged at temperatures ranging from 653K to 845K. The addition of Cu and Mg causes a decrease in the eutectic reaction temperature of Al-10Si-5Fe-1Zr alloy from 841K to 786K and results in a decrease of flow stress at the given forging temperature. TEM observation revealed that in addition to Al-Fe based intermetallics, $Al_2Cu$ and $Al_2CuMg$ intermetallics appeared. The volume fraction of intermetallic dispersoids increased by the addition of Cu and Mg. Compressive strength of the present alloys was closely related to the volume fraction of intermetallic dispersoids.

• 한국표면공학회지
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• 제31권5호
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• pp.297-303
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• 1998

The influences of vanadium addition on the cavitation erosion resistance pf Fe-Cr-Ni-Si-C hardfacing alloy were investigated using a vibratory apparatus up to 30 hrs. It was shown that 1wt.%V additioned alloy improved the resistance to cavitation damage. However, further increase in V content up to 2wt.% reduced the cavitation erosion resistance. It was considered that the addition of V developed the cavitation erosion resistance by reducing the stacking fault energy of Fe-Cr-Ni-Si-C alloy. However, the further increase in V content seemed to reduce the cavitation erosion resistance by increasing the matrix/carbide interfacial area, which was the preferential sites of the cavitation damage.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2011년도 임시총회 및 하계학술연구발표회
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• pp.134-135
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• 2011

The fundamental properties of $Fe_3P$ intermetallic compound was investigated in terms of the FLAPW method within GGA. The FM state of $Fe_3P$ was found to be energetically more stable compared to the NM one. It is consistent with the experiment. In addition, the calculated magnetic moments of Fe atoms were calculated to be 2.367, 1.665, and 2.104 ${\mu}B$ for FeI, FeII, and FeIII atoms, respectively.

• 한국자기학회지
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• 제7권1호
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• pp.44-48
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• 1997

약 30 nm의 미세결정립으로 구성된 ( .alpha. -Fe)-(Nd$_{2}$Fe$_{14}$B$_{1}$)형 저 Nd함유 Nd-Fe-B계 합금이 급속응고법으로 제조된 비정질상으로 부터 결정화하여 제조되었다. Nd$_{4}$Fe$_{82}$B$_{10}$Mo$_{3}$Cu$_{1}$ 조성에 Ga의 첨가는 각형성 개선효과와 함께 잔류자화를 1.29 T까지 증가시킨다. Nd의 함유량을 증가시킨 초미세결정립 Nd$_{5}$Fe$_{81}$B$_{9}$Mo$_{3}$Cu$_{1}$Ga$_{1}$ 합금의 Nd$_{2}$Fe$_{81}$B$_{9}$Mo$_{3}$Cu$_{1}$Ga$_{1}$ 합금의 잔류자화, 보자력 및 최대자기에너지적은 각각 1.24 T, 257.4 kA/m(3.23 kOe), and 100.3 kJ/m$^{3}$(12.6 MGOe)이다.다.

• 자원리싸이클링
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• 제26권4호
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• pp.95-100
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• 2017

본 연구에서는 폐 PCB(printed circuit board) 표면을 긁어내어 회수한 구리분말을 용융하는 과정에서 용융온도 저감과 정제를 위하여 플럭스로 $Fe_2O_3$를 첨가하였으며, $Fe_2O_3$ 첨가량 및 온도에 따른 구리의 회수율과 불순물 농도에 미치는 영향을 조사하였다. 구리 회수율은 반응온도와 $Fe_2O_3$의 첨가비율이 증가할 수 록 증가하였다. 그리고 구리 중 산소, 실리콘, 철의 농도는 $Fe_2O_3$ 첨가량이 증가할수록 감소하였다. $Fe_2O_3$를 첨가하여 반응시킨 후의 슬래그를 XRD로 분석하여 fayalite($2FeO{\cdot}SiO_2$)와 철산화물을 확인하였다. 따라서 fayalite 슬래그의 생성에 의한 슬래그의 융점과 점도 감소가 구리 회수율의 증가에 크게 기여한 것으로 생각된다.

• 한국가축번식학회지
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• 제23권3호
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• pp.229-237
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• 1999

본 연구는 돼지 동결-융해 정자의 전배양시 aseorbie acid (Ase)와 ferrous sulfate (Fe$^{2＋}$)가 정자의 수정능력획득, 첨체반응 및 난자내 침입능력에 미치는 영향을 검토하였다. 정자의 전배양시 0~1.0 mM의 Fe$^{2＋}$의 첨가는 비전배양에 비해 높은 첨체반응 (P＜0.05) 및 정자침입율을 얻었다. 이와 같은 결과는 0~0.5mM의 Ase 첨가 시 첨체반응율에서는 같은 결과를 나타냈지만 정자침입율은 오히려 정자의 전배양 보다는 비전배양시 높은 비율을 나타냈다. 한편, Fe$^{2＋}$가 함유 되어있는 배양액내에서 2시간동안 정자의 전배양시 0.1 mM Asc의 첨가는 0.5 mM Ase의 첨가에 비해 유의적으로 높은 첨체반응율을 나타냈으나 (P＜0.05), Ase의 농도사이에서 정자침입율에는 차이가 없었다. 또한, Ase가 함유된 배양액내에서 정자의 전배양시 0.1 mM Fe$^{2＋}$를 첨가했을 때 첨체반응율은 Fe$^{2＋}$ 무첨가시 유의적으로 높았으나 (P＜0.05), 오히려 가장 낮은 정자침입율을 나타냈다. 이와 같은 결과는 체외에서 돼지정자의 처리시 Fe$^{2＋}$ 또는 Ase의 첨가와 정자의 전배양에 의해 첨체반응과 정자침입에 효과적인 작용을 하는 것으로 생각된다.

• 한국주조공학회지
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• 제18권4호
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• pp.357-363
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• 1998

Microstructure of A356 aluminium alloys cast in a permanent mold was investigated by optical microscope and image analyzer, with particular respect to the shape and size distribution of iron intermetallics known as ${\beta}-phase$ ($Al_5FeSi$). Morphologies of the ${\beta}-phase$ was found to change gradually with the Be:Fe ratio like these. In Be-free alloys, ${\beta}-phase$ with needlelike morphology was well developed, but script phase was appeared when the Be:Fe ratio is above 0.2:1. With the Be:Fe ratios of 0.4:1-1:1, script phase as well as Be-rich phase was also observed. In case of higher Be addition, above 1:1, Be-rich phase was observed on all regions of the specimens, and increasing of the Be:Fe ratios gradually make the Be-rich phase coarse. It was also observed that the ${\beta}-phase$ with needlelike morphology was coarsened with increase of the Fe content in Be-free alloys. However, in Be-added alloys, length and number of these ${\beta}-phases$ were considerably decreased with the increased Be:Fe ratio. It was concluded that Fe impurity element to be crystallized into needlelike intermetallics was tied up by Be addition element, and new phases were crystallized into script or Be-rich intermetallics.

• 한국자기학회지
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• 제5권5호
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• pp.412-415
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• 1995

By adding 1wt.% $HfB_{2}$ into $Nd_{3-4}Fe_{77-78.5}B_{18.5}$ alloys, the grain growth of $Fe_{3}B/Nd_{2}Fe_{14}B$ composite phases during annealing was found to be hindered by 40~50%. It is proposed that the addition of $HfB_{2}$ leads to the formation of fine dispersoids of $HfB_{2}$ in the $Fe_{3}B/Nd_{2}Fe_{14}B$ composite magnet. The maximum energy product($(B.H)_{max}$) as well as intrinsic coercivity($_{i}H_{c}$) for the $Nd_{3}Fe_{78.5}B_{18.5}\;+\;1wt.%\;HfB_{2}$ alloy were enhanced by more than 25% $(B.H)_{max}=10\;MGOe,\;_{i}H_{c}=2.5\;kOe)$ due to the addition of $HfB_{2}$ while remanent magntization($B_{r}$) was reduced slightly. Itis deduced that the formation of fine dispersoids will also play a role of magnetic domain pinning.

• 한국재료학회지
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• 제21권7호
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• pp.357-363
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• 2011

In this paper, high temperature oxidation behavior of newly developed alloys, Ti-6Al-4Fe and Ti-6Al-1Fe, is examined. To understand the effect of Fe on the air oxidation behavior of the Ti-Al-Fe alloy system, thermal oxidation tests are carried out at $700^{\circ}C$ and $800^{\circ}C$ for 96 hours. Ti-6Al-4V alloy is also prepared and tested under the same conditions for comparison with the developed alloys. The oxidation resistance of the Ti-Al-Fe alloy system is superior to that of Ti-6Al-4V alloy. Ti-6Al-4V shows the worst oxidation resistance for all test conditions. This is not a result of the addition of Fe, but rather it is due to the elimination of V, which has deleterious effects on high temperature oxidation. The oxidation of the Ti-Al-Fe alloy system follows the parabolic rate law. At $700^{\circ}C$, Fe addition does not have a noticeable influence on the amount of weight gain of all specimens. However, at $800^{\circ}C$, Ti-6Al-4Fe alloy shows remarkable degradation compared to Ti-6Al-1Fe and Ti-6Al. It is discovered that the formation of $Al_2O_3$, a diffusion resistance layer, is remarkably hindered by a relative decrease of the ${\alpha}$ volume fraction. This is because Fe addition increases the volume fraction of ${\beta}$ phase within the Ti-6Al-xFe alloy system. Activities of Al, Ti, and Fe with respect to the formation of oxide layers are calculated and analyzed to explore the oxidation mechanism.

• Journal of Magnetics
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• 제10권1호
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• pp.28-32
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• 2005

The magnetic properties and ordering behavior of Nb-doped FePt alloy films prepared by dc-magnetron sputtering were investigated. It was found that Nb addition retarded the ordering reaction from the disordered face-centered-cubic (fcc) Al phase to the ordered face-centered-tetragonal (fct) L1₀ phase. The tetragonality (c/a ratio) of the ordered fct L1₀ phase increased with the Nb concentration. Nb addition hampered c-axis contraction during ordering, probably because the larger Nb atoms occupy Pt sites. Consequently, the coercivity and magnetocrystalline anisotropic energy of Nb-doped FePt alloy films are lower than those of un-doped FePt film under equivalent annealing conditions.