• 한국자기학회지
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• 제19권2호
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• pp.62-66
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• 2009

연자성 금속재료인 $Fe_{94}Si_5Cr_1$을 30시간 볼밀 한 후 주사전자현미경을 사용하여 관찰한 결과 볼밀 가공한 FeSiCr의 입자들이 구형에서 편상으로 변함을 확인하였다. FeSiCr을 실리콘 고무와 혼합하여 핸드폰용 전파흡수체를 제조하고 network analyzer을 이용하여 두께에 따른 FeSiCr-고무 전파흡수체의 전파흡수특성 및 재료정수를 측정하였으며, 그들의 상관관계를 비교 조사하였다. 그 결과 sheet형 전파흡수체 두께에 따라서 정합주파수가 낮은 주파수 대역으로 shift 됨을 알 수 있고, 1.3 mm의 두께로 제조한 전파흡수체에서는 이동통신주파수 대역인 1.86 GHz에서 -8.3 dB의 반사손실을 보여주었다.

• 수산해양기술연구
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• 제32권4호
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• pp.411-420
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• 1996

The structure of the scale formed on the surface of Fe - Cr - X alloys exposed to 1143K high sulfidation($Ps_2$ = 1.11$\times$$10^-7$ atm, $Po_2$ = 3.11$\times$$10^-20$ atm) or sulfidation/oxidation(($Ps_2$= 1.06$\times$$10^-7$ atm, ($Po_2$ = 3.11$\times$$10^-18$ atm) environment has been observed and analysed using XRD, SEM/EDS. To investigate the possibility of protective film formed on the surface of the alloys, Aluminium, Nickel were selected as alloying elements. Thermodynamic phase stability diagram was used to predict the reaction path of scale formed on Fe - Cr - X alloys. Parabolic rate constant($K_p$) value with 6wt% Al in Fe - 25Cr alloy decreased significantly compared with the Fe - 25Cr alloy without 6wt% Al. Since thin layer of defect free sulfide film, (Al, Cr)Sx, was formed at the alloy/scale interface. Fe - rich sulfide scale at outer layer and Cr - rich sulfide scale containing porosity at inner layer of Fe - 25Cr alloy have been observed. The reaction path for these scales could be predicted by the thermodynamic stability diagram.

• 한국분말재료학회지
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• 제12권1호
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• pp.43-50
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• 2005

Mechanical alloying using high-energy ball mill and subsequent spark plasma sintering (SPS) process was applied to Al-Fe-Cr and Al-Fe-Mo powder mixture to investigate effects of Cr and Mo addition on thermal stability of Al-Fe, and thereby to enhance its thermal stability up to $500^{\circC}$. Various analytical techniques including micro-Vickers hardness test, SEM, TEM, X-ray diffractometry and corrosion test were carried out. It was found that addition of Cr and Mo to Al-Fe system played a role of grain growth inhibitor of matrix Al and some precipitates such as $Al_3Fe$ during SPS and subsequent heat treatment. The inhibition of grain growth resulted in increased Vickers hardness and thermal stability up to $500^{\circC}$ comparing to those of Al-Fe alloy system.

• 한국세라믹학회지
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• 제31권7호
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• pp.767-771
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• 1994

In a salb-preheating furnace of steel-making industry, the oxidation/degradation behavior of Cr3C2 ceramic composited dkid button reaction with scale in Fe-oxide system occurs and was thermodynamically examined. The reaction of scale with Cr3C2 skid button produces Cr3C2(s) and C(s), and Co gas is then evolved from the reaction of C(s) with Fe-scale. Cr3C2(s) from oxidation of Cr3C2(s) reacted with Fe-oxide(s) becomes high-melting chromite. The chromite acts as protection layer against further oxidation and improves resistance of the reaction of Cr3C2 skid button with Fe-scale.

• Corrosion Science and Technology
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• 제2권1호
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• pp.12-17
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• 2003

The effects of Cr content and film formation potential on electronic behaviors of the passive film on Fe-Cr alloys were investigated in borate buffer solution. Influence of pH on passive films of both Fe-Cr and Fe-Cr-Mo alloys was also investigated. Mott-Schottky and cyclic voltammetry techniques were used to elucidate electronic behaviors of passive films and their electrochemical characteristics. AES analysis of passive films was carried out. Results showed that doping density decreased as Cr content and film formation potentials increased. The addition of Mo to Fe-Cr alloy had little influence on donor densities in pH 9.2 solution but some effects on the decrease in donor densities in pH 1.6 acidic solution.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2001년도 추계연구발표회 논문개요집
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• pp.28-29
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• 2001

• 한국결정성장학회지
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• 제18권6호
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• pp.248-252
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• 2008

전기전도성이 우수하면서 입자 크기가 작은 $LiFePO_4$ 분말을 얻기 위해서, 이종원소(Cr+B 또는 Cr+Al) 도핑이 $LiFePO_4$의 전기전도도에 미치는 영향과 열처리 조건이 입자 크기에 미치는 영향에 대해서 조사하였다. 조성이 $LiFe_{0.965}Cr_{0.03}B_{0.005}PO_4$ and $LiFe_{0.065}Cr_{0.03}Al_{0.005}PO_4$인 두 종류의 분말을 기계화학적 밀링법으로 혼합 후 $675{\sim}759^{\circ}C$에서 $5{\sim}10$시간 열처리하여 합성하였다. 이종원소 도핑은 입자성장을 촉진하였고 전기전도도를 높이는 효과가 있었다. $LiFe_{0.065}Cr_{0.03}Al_{0.005}PO_4$의 전기전도도는 $1{\times}10^{-8}S/cm$로 도핑하지 않은 것의 $5{\times}10^{-10}S/cm$보다 높았다.

• 한국자기학회지
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• 제8권6호
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• pp.362-368
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• 1998

반강자성 Cr86Al14계 스핀밸브막의 자기특성과 내열 내식성에 대해 연구하엿다. Cr86Al14스핀밸브막의 자기적성질은 강자성층, 자성층 및 비자성층두께에 의존하였으며, glass/Cr86Al14(600$\AA$)/Ni81Fe19(50$\AA$)/Cu(40$\AA$)/Ni81Fe19(40$\AA$)구조에서의 교환결합자장(Hex)은 20 Oe, 자기저항비(MR ratio (%))는 2%를 나타내었다. Cr96Al14 및 Fe50Mn50 스핀밸브막은 annealing온도가 증가함에 따라 모두 Hex 및 MR비가 감소하는 경향을 나타내엇으나 FeMn막에 비해 CrAl막이 우수하여, FeMn막은 15$0^{\circ}C$, CrAl막은 25$0^{\circ}C$에서 Hex 및 MR비값을 상실하였다. 또한 가혹한 환경에서의 스핀밸브막의 부식저항성을 평가하고자 35$^{\circ}C$,90% 습도상태의 챔버내에서 Hex와 MR비값의 변화를 관찰한 결과 CrAl막의 경우에는 Hex 및 MR비 값이 시간이 경과해는 변화지 않았으나, FeMn막은 15일정도 경과하자 거의 상실하는 결과를 나타냈다. SEM관찰결과 FeMn막은 pitting이 나타났으며 15일정도 경과후에는 박리가 발생하였다.

• 한국입자에어로졸학회지
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• 제8권2호
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• pp.83-88
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• 2012

The electrical wire explosion process in liquid media is promising for nano-sized metal and/or alloy particles. The hybrid Pt/Fe-Cr-Al and Pt/Ni-Cr-Fe nanoparticles for exhaust emission control system are synthesized by electrical wire explosion process in liquid media. The alloy powders have spherical shape and nanometer size. According to the wire component, while Pt/Fe-Cr-Al nanoparticles are shown the well dispersed Pt on the Fe-Cr-Al core particle, Pt/Ni-Cr-Fe nanoparticles are shown the partially separated Pt on the Ni-Cr-Fe core particle. Morphologies and component of two kinds of hybrid nano catalyst particles were characterized by transmission electron microscope and energy dispersive X-ray spectroscopy analysis.

• 동력기계공학회지
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• 제9권1호
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• pp.70-75
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• 2005

The damping property of Fe-12Cr-22Mn-X alloys has been investigated to develop high damping and high strength alloy. Particularly, the effect of the phase of austenite, alpha and epsilon martensite, which constitute the structure of the alloys Fe-12Cr-22Mn-X alloys, on the damping capacity at room temperature has been investigated. Various fraction of these phases were formed depending on the alloy element and cold work degree. The damping capacity is strongly affected by ${\varepsilon}$ martensite while the other phase, such as ${\alpha}'$ martensite, actually exhibit little effect on damping capacity. In case of Fe-12Cr-22Mn-3Co alloy, the large volume fraction of ${\varepsilon}$ martensite formed at about 30% cold rolling, and in case of Fe-12Cr-22Mn-1Ti alloy, formed at about 20% cold rolling and showed the highest damping capacity. Damping capacity showed higher value in Fe-12Cr-22Mn-1Ti alloy than one in Fe-12Cr-22Mn-3Co alloy.