• 열처리공학회지
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• 제35권3호
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• pp.150-158
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• 2022

The effects of scandium addition on the Al-6Si-2Cu Alloy were investigated. The Al-6Si-2Cu-Sc alloy was prepared by gravity die casting process. In this study, scandium was added at 0.2 wt%, 0.4 wt%, 0.8 wt%, and 1.0 wt%. The microstructure of Al-6Si-2Cu-Sc alloy was investigated using Optical Microscope, Field Emission Scanning Electron Microscope, Electron Back Scatter Diffraction, and Transmission Electron microscope. The microstructure of Al-6Si-2Cu alloy with scandium added changed from dendrite structure to equiaxed crystal structure in specimens of 0.4 wt% Sc or more, and coarse needle-shape eutectic Si and β-Al₅FeSi phases were segmented and refined. The nanosized Al₃Sc intermetallic compound was observed to be uniformly distributed in the modified Al matrix.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.153.2-158
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• 1999

A study has been made to investigate how the fomability of Ti-10V-2Fe-3Al alloy is related to the initial microstructure and process variables such as temperature and strain rate. It has been found that the deformation resistance at high temperature is increased with the increase in the thickness of grain boundary a (GB)a and/or acicular a phase and however the effect of a morphology on the hot formability is considered insignificant due to the breakage of GB a and/or acicular a into several equiaxed a particles

• 한국재료학회지
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• 제13권12호
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• pp.791-795
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• 2003

The oxidation behaviour of Fe-XAl-0.1Y(X= 5, 10, 14 wt.%) alloys were investigated at 1073, 1173 and 1273 K in oxygen/ nitrogen gas atmosphere for 1∼24 hrs using SEM/EDX, XRD and EPMA. The weight changes of Fe-XAl-0.1Y alloys followed the parabolic rate law. Oxidation rates of 10Al and 14Al alloys were ten times lower than that of 5Al alloys. This is attributed to the formations of protective $A1_2$$O_3$oxides on the surface of 10Al and 14Al alloys. The oxidation product scales of the 5Al alloy showed that thick iron oxide scales($Fe_2$$O_3$, $Fe_3$$O_4$) containing porosities formed during early stages of oxidation. With continued oxidation, aluminum oxide was formed at the alloy/scale interface.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1290-1291
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• 2006

Fabrication of $Fe_3AlC$ matrix in-situ composite, reinforced by a FeAl phase, was studied by using the powder metallurgical processing route. Especially, in order to disperse the second phase more finely, we chose the mechanical alloying process. We investigated the microstructural and mechanical properties of the consolidated material. After consolidation by vacuum hot pressing, the compact showed almost full density and consisted of a $Fe_3AlC$ matrix and FeAl second phase (average particle size was less than 1m). The compact showed HV746, which was higher than that of the arc melted $Fe_3AlC$ monolithic material, HV603.

• Advanced Composite Materials
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• 제18권4호
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• pp.339-350
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• 2009

Al-Fe-V-Si alloys reinforced with SiC particles were prepared by multi-layer spray deposition technique. Both microstructures and mechanical properties including hardness and tensile properties development during hot exposure process of Al-8.5Fe-1.3V-1.7Si, Al-8.5Fe-1.3V-1.7Si/15 vol% $SiC_P$ and Al-10.0Fe-1.3V-2Si/15 vol% $SiC_P$ were investigated. The experimental results showed that an amorphous interface of about 3 nm in thickness formed between SiC particles and the matrix. SiC particles injected silicon into the matrix; thus an elevated silicon concentration was found around $\alpha-Al_{12}(Fe,\;V)_3Si$ dispersoids, which subsequently inhibited the coarsening and decomposition of $\alpha-Al_{12}(Fe,\;V)_3Si$ dispersoids and enhanced the thermostability of the alloy matrix. Moreover, the thermostability of microstructure and mechanical properties of Al-10.0Fe-1.3V-2Si/15 vol% $SiC_P$ are of higher quality than those of Al-8.5Fe-1.3V-1.7Si/15 vol% $SiC_P$.

• 연구논문집
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• 통권22호
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• pp.115-125
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• 1992

Mechanical properties and microstructure were investigated on vacuum induction melted $Fe_3A1$base alloys of $DO_3$ structure. Specal emphasis were put on the effect of alloy chemistry, grain size and process(rolling, directional solidification) on mechanical properties of Fe-22.5-39at.%Al at elevated temperature between room temperature and $800^{\circ}C$. grain size of as-cast alloys is refined by rolling from 1mm to $80\mum$. Tensile strength of Fe-24.lat.%AI was about 404MPa at the critical ordering temperature, and the fracture strain of the alloy was 1-2% at room temperature. An inverse temperature dependence of the strength is noticed as-cast $Fe_3A1$. The presence of Cr and Zr do not affect the room temperature ductility and high temperature strength. Fracture strain of directionally solidified(DS) $Fe_3A1$ is about 1%at room temperature, but is about 60%at. $T_C$(550^{\circ}C)$. Tensile strength of DS alloy is lower than that of as-cast alloy at $530^{\circ}C$ and $430^{\circ}C$. Failure mode at room temperature varies from transgranular fracture to intergranular fracture with the addition of Al. the failure mode also varies from mixed(transgranular+ intergranular) mode between room temperature and $500^{\circ}C$ to intergranular mode above $550^{\circ}C$

• 열처리공학회지
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• 제37권3호
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• pp.121-127
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• 2024

We investigate the effect of T6 heat treatment on the microstructure and mechanical properties of AA365 (Al-10.3Si-0.37Mg-0.6Mn-0.11Fe, wt.%) alloy fabricated by vacuum-assisted high pressure die casting by means of thermodynamic calculation, X-ray diffraction, scanning and transmission electron microscopy, and tensile tests. The as-cast alloy consists of primary Al (with dendrite arm spacing of 10~15 ㎛), needle-like eutectic Si, and blocky α-AlFeMnSi phases. The solution treatment at 490 ℃ induces the spheroidization of eutectic Si and increase in the fraction of eutectic Si and α-AlFeMnSi phases. While as-cast alloy does not contain nano-sized precipitates, the T6-treated alloy contains fine β' and β' precipitates less than 20 nm that formed during aging at 190℃. T6 heat treatment improves the yield strength from 165 to 186 MPa due to the strengthening effect of β' and β' precipitates. However, the β' and β' precipitates reduce the strain hardening rate and accelerate the necking phenomenon, degrading the tensile strength (from 290 to 244 MPa) and fracture elongation (from 6.6 to 5.0%). Fractography reveals that the coarse α-AlFeMnSi and eutectic Si phases act as crack sites in both the as-cast and T6 treated alloys.

• 마이크로전자및패키징학회지
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• 제24권1호
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• pp.1-8
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• 2017

Fe-9.8Si-6.0Al mother alloy was manufactured using by Fe-3.5Si recycled scrap and Si powder. And then, soft magnetic alloy powder of $D_{50}$ size and sphere type were prepared by gas atomization process. To obtain the soft magnetic powder of a high aspect ratio, in the first, we conducted the ball milling process for 8 hours. And heat treatment was performed under $650^{\circ}C$, 2 hours and $N_2$ atmosphere condition for reducing the residual stress of the powder. Based on these process, we made around $50{\mu}m$ diameter Fe-9.8Si-6.0Al powder, which morphology and shape was a similar to the commercial Fe-Si-Al powder. Finally, the soft magnetic sheets were prepared by tape casting process using by those powders. The permeability of the tape casting sheet was measured, and we confirmed the possibility of reusing to the soft magnetic materials of Fe-Si electric sheet scrap.

• 한국진공학회지
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• 제12권S1호
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• pp.60-62
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• 2003

In this study we report the results of ab initio first-principles calculations to investigate the possibility of metamagnetic behavior in Fe$_3$Al alloy. We used the WIEN2k package of full-potential linearized-augmented- plane-wave method within the local-spin-density approximation to the density-functional theory. The exchange-correlation functional is the generalized-gradient approximation of Perdew-Burke-Ernzerhof. The theoretical lattice constant, which is about 0.5% smaller than the experimental one, is obtained by minimizing the total energy. If the volume decreases about 9 % from the equilibrium, the total magnetic moment decreases abruptly from 4.6 $\mu_{B}$/f.u. to 4.0 $\mu_{B}$/f.u. Since this change is considerably large (∼14%), it is possible to measure by a simple high-pressure experiment at about 180 kbar.

• 한국자기학회지
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• 제5권1호
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• pp.1-7
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• 1995

급속응고법중 단롤법을 이용하여 Fe-B계에 Co 및 Nb과 Al이 치환된 (Fe/sub 0.85/Co/sub 0.15/)/sub 75/ Al/sub 7/B/sub 18-x/Nb/sub x/(x = 2, 4, 6)와 (Fe/sub 0.85/Co/sub 0.15/)/sub 75/Al/sub y/B/sub 21-y/Nb/sub 4/ (y = 3, 5, 7, 9)합금을 급속응고장치로 단롤법을 이용하여 리본상으로 제작한후, 이들 합금의 초미세결정립 제조 가 능성과 자기적 특성의 조성 및 온도 의존성을 조사하였다. 초미세결정립합금은 y = 9를 제외한 전조성에서 제조가 가 능하였다. 포화자화 값은 열처리 후 증가하였고 Nb 함량이 증가하면 감소하였으며 상대적으로 Al과 B의 영향은 적었 다. 50 kHz에서 조사한 초투자율은 초미세결정립이 형성된 후가 열처리 전보다 2배이상 증가하였으며, 항자력과 교류 자기이력손실은 반대로 1/2이하로 감소하였다.