• 한국재료학회지
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• 제11권1호
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• pp.34-38
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• 2001

Fe-28%Al($Fe_3Al$)과 Fe-28%Al-4%Cr($Fe_3Al-4Cr$) 금속간화합물을 대기중 1073, 1273, 1473k의 온도에서 최고 17일까지 장시간 산화시켰다. $Fe_3Al-4Cr$의 산화저항은 근본적으로 $Fe_3Al$과 거의 비슷하거나, 약간 우수하였다. $Fe_3Al$ 위에 형성된 산화물은 거의 순수한 ${\alpha}-AL_2O_3$로만 구성되어 있었으며, $Fe_3Al-4Cr$ 위에 형성된 산화물은 약간의 Fe와 Cr 이온이 고용된 ${\alpha}-AL_2O_3$로 구성되어 있었다. 외부산화막을 형성하기 위해 모재원소의 외부확산에 의해 산화물-모재 계면에는 Kirkendall 기공이 존재하였다. $Fe_3Al(-4Cr)$ 표면에 형성된 산화막은 1273k가지는 비교적 얇고 치밀하였으나, 1473k에서 산화막의 박리와 함께 상대적으로 큰 무게증가가 발생하였다.

• 한국재료학회지
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• 제12권11호
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• pp.845-849
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• 2002

Alloys of $Fe_3$Al, $Fe_3$Al-6Cr, $Fe_3$Al-4Cr-1Mo, $Ni_3$Al, and $Ni_3$Al-2.8Cr were oxidized at $1000^{\circ}C$ in air, and the oxide scales formed were studied using XRD. SEM, EPMA, and TEM. The oxide scales that formed on $Fe_3$Al-based alloys consisted primarily of $\alpha$-$Al_2$$O_3$ containing a small amount of dissolved Fe and Cr ions, whereas those that formed on $Ni_3$Al-based alloys consisted primarily of $\alpha$-$Al_2$$O_3$, together with a small amount of $NiAl_2$$O_4$, NiO and dissolved Cr ions. For the entire alloys tested, nonadherent oxide scales formed, and voids were inevitably existed at the scale-matrix interface.

• 한국결정성장학회지
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• 제9권2호
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• pp.185-190
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• 1999

$Al_2O_3/Fe$ 복합재료 제조는 반응소결법에 의한 2단계 공정을 통해서 제조되었으며 이 공정은 장비가 간단하고 near-net-shape이 가능한 장점이 있다.$Al_2O_3/Fe$ 복합재료를 제조하기 위해서 1차로 $650^{\circ}C$에서 5시간동안 산화/환원 처리를 행하고 $1200^{\circ}C$에서 2차로 소결처리를 행하였다. 제조된 복합재료의 상분석결과 $\alpha$-Fe 와 $\alpha$-$Al_2O_3/Fe$가 주된 상이었고 소량의 $FeAl_2O_4$가 검출되었다. 이 소량의 $FeAl_2O_4$상은 Fe가 $Al_2O_4$기공을 채우는 것을 방해함으로써 소결동안 미세구조 내에 약간의 기공을 발생시킨다.

• 한국주조공학회지
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• 제33권3호
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• pp.103-112
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• 2013

Effect of Fe and Mn contents on the tensile properties of Al-4 wt%Mg-0.9 wt%Si alloy system has been studied. Common phases of Al-4 wt%Mg-0.9 wt%Si alloy system were ${\alpha}$-Al, $Mg_2Si$, ${\alpha}-Al_{12}(Fe,Mn)_3Si$ and ${\beta}-Al_5FeSi$. As Fe content of Al-4 wt%Mg-0.9 wt%Si alloy system increased from 0.15 wt% to above 0.3 wt%, ${\beta}-Al_5FeSi$ compound appeared. When Mn content of the alloy increased from 0.3 wt% to 0.5 wt%, morphology of plate shaped ${\beta}-Al_5FeSi$ compound changed to chinese script ${\alpha}-Al_{12}(Fe,Mn)_3Si$. As Fe content of Al-4 wt%Mg-0.9 wt%Si-0.3 wt%Mn alloy increased from 0.15 wt% to 0.4 wt%, tensile strength of the as-cast alloy decreased from 191 MPa to 183 MPa and, elongation of the alloy also decreased from 8.0% to 6.2%. Decrease of these properties can be explained as the formation of plate shape, ${\beta}-Al_5FeSi$ phase with low Mn/Fe ratio of the alloy. However, when Mn content of Al-4 wt%Mg-0.9 wt%Si-0.3 wt%Fe alloy increased from 0.3 wt% to 0.5 wt%, tensile strength of as-cast alloy increased from 181 MPa to 194 MPa and, elongation of the alloy increased from 6.8% to 7.0%. These improvements attribute to the morphology change from ${\beta}-Al_5FeSi$ phase to chinese script, ${\alpha}-Al_{15}(Fe,Mn)_3Si_2$ phase shape-modified from with high Mn/Fe ratio of the alloy.

• 한국주조공학회지
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• 제33권6호
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• pp.233-241
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• 2013

Effect of Fe and Mn contents on the castability of Al-9wt%Si-xMg-yFe-zMn alloy has been studied. The alloy was composed of ${\alpha}$-Al phase, Al+eutectic Si phase, ${\beta}$-Al5FeSi compound and chinese script ${\alpha}$-$Al_{15}(Mn,Fe)_3Si_2$ compound. ${\beta}$-$Al_5FeSi$ and ${\alpha}$-$Al_{15}(Mn,Fe)_3Si_2$ compounds assumed to effect the fluidity and shrinkage behaviors of the alloy during solidification due to the crystallization of ${\alpha}$-$Al_{15}(Fe,Mn)_3Si_2$ and ${\beta}$-$Al_5FeSi$ compounds above eutectic temperature. As Fe and Mn contents of Al-9wt%Si-0.3wt%Mg system alloy increased from 0.15wt% to 0.6wt% and from 0.3wt% to 0.7wt%, fluidity of the alloy decreased by 5.7% and 3.3%, respectively. And as Mg content of Al-9wt%Si-0.45wt%Fe-0.5wt%Mn system alloy increased from 0.3wt% to 0.4wt%, fluidity of the alloy decreased by 8.6%. When Fe content of the alloy increased from 0.15wt% to 0.6wt%, macro shrinkage ratio decreased from 6.1% to 4.1%, and micro shrinkage ratio increased from 0.04% to 0.24%. Similarly, Mn content of the alloy increased from 0.3wt% to 0.7wt%, macro shrinkage ratio decreased from 6.0% to 4.5% and micro shrinkage ratio increased from 0.12% to 0.18%. Judging from the castability of the alloy, Al-9wt%Si-0.3wt%Mg alloy with low content of Fe and Mn, 0.1wt% Fe and 0.3wt% Mn, is recommendable.

• 한국주조공학회지
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• 제23권2호
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• pp.77-85
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• 2003

Some alloying elements such as Cr, B, Ti and Si were added individually or as a mixture to Fe-30 at.%Al alloys. The alloys were melted using an arc furnace and then heat-treated for homogenization at 1000$^{\circ}C$ for 7 days and followed by rolling at 1000$^{\circ}C$. The alloying elements on rolling characteristics were investigated by the microstructures and fracture mode before and after rolling. The microstructures before rolling showed that all of the alloys had equiaxed grains. On the other hand, the microstructures of rolling plane as well as its perpendicular plane became elongated after rolling. The alloys such as Fe-30Al, Fe-30Al-3Ti, Fe-30Al-0.5B, Fe-30Al-5Cr and Fe-30Al-3Ti-0.5B revealed better rolling behaviour from the point that intergranular and cleavage fractures were not fundamentally occurred. But the addition of 5Ti or 3Si to Fe-Al alloys had detrimental effects. The Ti-added alloy system such as Fe-30Al-5Ti, Fe-30Al-5Ti-5Cr, Fe-30Al-3Ti-5Cr and Fe-30Al-5Ti-0.5B were cracked through grain and showed cleavage fracture. The Si-added alloy system such as Fe-30Al-5Si, Fe-27Al-3Si and Fe-27Al-5Cr-3Si were cracked along the grain boundary and showed intergranular fracture. $DO_3{\leftrightarrow}B_2$ transition temperature of Fe-30at.%Al alloy was 520$^{\circ}C$, whereas the addition of 3Ti and 3Ti+0.5B comparably increased the temperature to 797 and 773$^{\circ}C$, respectively.

• 한국주조공학회지
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• 제31권1호
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• pp.18-25
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• 2011

Effect of Fe and Mn contents on the tensile properties has been studied in Al-9wt%Si-0.3wt%Mg alloy. As Fe content of Al-9wt%Si-0.3wt%Mg-0.5wt%Mn alloy increased from 0.15wt% to 0.45wt%, tensile strength of as-cast alloy decreased from 192 MPa to 174 MPa, and elongation of the alloy also decreased from 4.8% to 4.2%. Decrease of these properties can be explained as the formation of plate shape, ${\beta}-Al_5FeSi$ phase with high Fe/Mn ratio of the alloy. However when Mn content of Al-9wt%Si-0.3wt%Mg-0.45wt%Fe alloy increased from 0.3wt% to 0.5wt%, tensile strength of T6 aged alloy increased from 265 MPa to 275 MPa, and elongation of the alloy increased from 2.3% to 3.6%. These improvements attribute to chinese script, ${\alpha}-Al_{15}(Mn,Fe)_3Si_2$ phase shape-modified from ${\beta}-Al_5FeSi$ phase with low Fe/Mn ratio of the alloy.

• 한국자기학회지
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• 제9권6호
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• pp.296-300
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• 1999

DC 마그네트론 스퍼터링 방법으로 금속 마스크를 사용하여 십자형태로 substrate/Ta/NiFe/FeMn/NiFe/CoFe/Al2O3/CoFe/NiFe와 substrate/Ta/NiFe/CoFe/Al2O3/CoFe/NiFe/FeMn/NiFe 스핀 터널링 접합 구조를 제조하였다. 이러한 구조에서 절연층(Al2O3)의 형성조건과 각 층의 두께와 파워에 대한 증착율에 변화를 주어 24.3%의 자기 저항비를 얻었다. 두 종류의 구조에 대한 자기적 특성 비교와 Corning glass 7059와 Si(111) 기판의 종류에 따른 결과를 비교하였으며 소자 제조때 수반되는 온도변화에 대한 특성변화를 알아보고자 열처리를 하였다. 열처리 결과 자기 저항비는 15$0^{\circ}C$까지는 어느 정도 일정한 값을 유지하다가 18$0^{\circ}C$ 열처리 후 갑자기 감소하는 결과를 얻었다.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 추계총회 및 연구발표회 초록집
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• pp.144.1-144
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• 2003

• 동력기계공학회지
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• 제10권2호
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• pp.83-88
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• 2006

Corrosion characterization of Fe-XAl-0.3Y(X=5, 10, 14 wt%) alloys in $0.1{\sim}1N$ sulphuric acid at room temperature was studied using potentiodynamic techniques. The morphology and components of corrosion products on surface of Fe-aluminide alloys were investigated using SEM/EDX, XRD. The potentiodynamic polarization curve of alloys exhibited typical active, passive, transpassive behaviour. Corrosion potential($E_{corr}$) and corrosion current density($I_{corr}$) values of Fe-XAl-0.3Y alloys followed linear rate law. $E_{corr}$ of 10Al alloy and 14Al alloy was ten times lower than 5Al alloy. Icorr of 14Al alloy was five times lower than 5Al alloy. The passive film on the surface of Fe-5Al-0.3Y alloy was formed iron oxide. Fe-10Al-0.3Y and Fe-14Al-0.3Y alloys passive films were aluminium oxide. especially, Fe-14Al-0.3Y alloy showed good corrosion resistance in $0.1{\sim}1N$ sulphuric acid. This is attributed to the forming of protective $Al_2O_3$ oxide on the surface of Fe-14Al-0.3Y alloy.