• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 춘계학술발표대회 논문집
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• pp.46-49
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• 2003

Aluminum based metal matrix composites(MMCs) are well known for their high specific strength, stiffness and hardness. They are gaining further importance because of their high wear resistance. In this study, Al/Saffil-20%, Al/Saffil-5%/Al2O3(particle type)-15% and Al/Saffil-5%/SiC(particle type)-15% hybird MMCs' wear behavior were characterized by the pin-on-disk test under various normal load The superior wear resistance was exhibited at Al/Saffil-5%/SiC(particle type)-15% MMCs. And this MMCs' predominant wear mechanism is subsurface cracking in the low load wear regime. Others(Al/Saffil-20%, Al/Saffil-5%/Al2O3(particle type)-15%) showed the similar wear resistance with each other at the same test condition. In the low load & room temperature condition, the wear resistance was improved due to the high hardness of the ceramic reinforcements. As the test load increased, the wear properties were governed by the wear properties of matrix.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.455-458
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• 2009

In this research, the effect of Sc on the micro structure and mechanical properties of Al-20Si alloy powders and their extruded bar was investigated. The Al-20wt%Si and Al-20wt%Si-0.6wr%Sc powders were produced by gas atomization. The micro structures of the alloy powders and extrude was examined by optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The alloy powders were subsequently canned, degassed and extruded in order to produce the alloy bulk. It was found that the micro structure of the Al-20Si alloy powder was refined and the mechanical properties was significantly improved by the addition of 0.6Sc.

• 한국세라믹학회지
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• 제39권4호
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• pp.413-419
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• 2002

$Al_2O_3$/TiC/SiC, $Al_2O_3$/SiC 및 $Al_2O_3$/TiC 복합체들을 고온가압소결로 제조하여 이들의 균열저항거동과 기계적 성질을 비교해 보았다. $Al_2O_3$에 $0.8{\mu}m$의 TiC가 30vol% 첨가된 $Al_2O_3$/TiC는 단일체 $Al_2O_3$와 비슷한 균열저항거동을 보이며 파괴인성은 전반적으로 10% 이내의 증가를 보이는데 그쳤지만 강도는 약 30% 증가하였다. $Al_2O_3$에 $3{\mu}m$ SiC가 30vol% 첨가된 $Al_2O_3$/SiC는 SiC 입자의 균열 접속으로 인해 증가하는 균열저항거동을 뚜렷이 보이면서 파괴인성이 긴 균열에서 약 75% 증가하였으나 강도는 다소 감소했다. $Al_2O_3$/TiC에 SiC 입자가 30 vol% 첨가된 $Al_2O_3$/TiC/SiC 복합체의 경우 단일체 $Al_2O_3$에 비해 긴 균열 거리에서 파괴인성이 50% 이상 증가된 6.6 MP${\cdot}\sqrt{m}$에 이르렀으며 강도 값도 약 20% 상승하였다. 그러나 큰 SiC 입자의 첨가로 인해 TiC 입자만 첨가된 $Al_2O_3$/TiC 복합체보다는 강도가 다소 낮았다. 또한 SiC 입자만 첨가된 $Al_2O_3$/SiC 복합체보다는 파괴인성이 다소 낮았는데, 이는 작은 TiC 입자들이 SiC 입계를 거칠게 만들어 균열접속을 일으키는 SiC 입자의 뽑힘 현상을 방해하였기 때문이다.

• 한국주조공학회지
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• 제20권2호
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• pp.89-96
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• 2000

The effects of modification processing on the refinement of primary Si and the wear behavior of hyper-eutectic Al-Si alloys have been mainly investigated. Refining effects of primary Si in Al-17%Si alloy was more efficient than that of B.390 alloy. Optimum condition of getting the finest primary Si microstructure was when AlCuP modifier is added into the melt at $750^{\circ}C$ and held it at $700^{\circ}C$ for 30 minutes. Wear loss in the specimens of as-cast condition decreases as the size of primary Si decreases, in the order of B.390 alloy, B.390 alloy with AlCuP addition, Al-17%Si alloy and Al-17%Si alloy with AlCuP addition. Wear loss in the aged condition of Al-17%Si alloy, B.390 alloy and B.390 alloy with AlCuP addition decreased due to the increase of compressive residual stress in the matrix by the aging treatment. While, wear loss increased in the aged specimens of Al-17%Si alloy with AlCuP addition and Hepworth addition in which compressive residual stress decreases by the aging treatment. Therefore, it is assumed that higher compressive residual stress in the matrix can reduce the wear loss in composite materials such as hyper-eutectic Al-Si alloys.

• 한국분말재료학회지
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• 제11권3호
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• pp.259-264
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• 2004

Aluminum based metal matrix composite reinforced with SiC particles was fabricated by the powder-in sheath rolling method. A stainless steel tube with outer diameter of 12 mm and wall thickness of 1mm was used as a sheath. Mixture of aluminum powder and SiC particles of which volume content was varied from 5 to 20vol.% was filled in the tube by tap filling and then rolled to 75% reduction at ambient temperature. The rolled specimen was sintered at 56$0^{\circ}C$ for 0.5hr. The tensile strength of the (SiC)$_{p}$/Al composite increased with the volume content of SiC particles, and at 20vol.% it reached a maximum of 100㎫ which is 1.6 times higher than unreinforced material. The elongation decreased with the volume content of $Al_{2}$O$_{3}$ particles. The mechanical properties of the (SiC)$_{p}$/Al composite fabricated by the powder-in sheath rolling is compared with that of (Al$_{2}$O$_{3}$)$_{p}$/Al composite by the same process.ess.

• 한국전기전자재료학회논문지
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• 제20권4호
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• pp.363-366
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• 2007

[ $Zn_2SiO_4:Mn$ ] green phosphors doped with $NH_4Cl$ and Al for PDP were synthesized by solid state reaction method. The luminescence of 532 nm in $Zn_2SiO_4:Mn$ phosphors was associated with $^4T_1{\to}^6A_1$ transition. Photoluminescence intensity of $Zn_2SiO_4:Mn$ doped with $NH_4Cl$ 15 mol% increased about two times as compared with that of $NH_4Cl$ non-doped sample. The color of the emission of Al-doped $Zn_2SiO_4:Mn$ phosphors changed to yellowish green.

• 한국주조공학회지
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• 제13권4호
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• pp.350-358
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• 1993

Aluminum base composites reinforced with various amount of SiC particles and Mg contents have been investigated by different fabrication method for twenty-years. In this paper, how the decomposition and dissolution behaviors of $SiCp(20{\mu}m)$ in the melt of Al composites arised was studied. As the results, the decomposition and dissolution of SiCp into the melt of Al composites increased with increase of the temperature above $720^{\circ}C$, and holding time at a given melting temperature. Because SiC is thermodynamically unstable in this Al-SiCp composite at temperature above the liquidus, SiCp dissolves and reacts with Al in matrix to form $Al_4C_3$ according to following chemical equation $4Al+3SiC{\rightarrow}Al_4C_3+3Si$, Si decomposed and dissolved from SiCp increases Si content of matrix, while liquidus temperature of matrix decrease with increase of SiC content in matrix. The hardness of SiCp decreased with increase of the melting temperature, the hardness of the matrix /particle interface increased with increase of the melting temperature due to increase of the $Mg_2Si$ and $Al_4C_3$ intermetallic compounds, etc.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2000년도 춘계학술강연 및 발표대회 강연 및 발표논문 초록집
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• pp.20-20
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• 2000

• 한국분말재료학회지
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• 제11권3호
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• pp.233-241
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• 2004

In this study, bottom-up type powder processing and top-down type SPD (severe plastic deformation) approaches were combined in order to achieve both full density and grain refinement of Al-20 wt% Si powders without grain growth, which was considered as a bottle neck of the bottom-up method using the conventional powder metallurgy of compaction and sintering. ECAP (Equal channel angular pressing), one of the most promising method in SPD, was used for the powder consolidation. The powder ECAP processing with 1, 2, 4 and 8 passes was conducted for 10$0^{\circ}C$ and 20$0^{\circ}C$ It was found by microhardness, compression tests and micro-structure characterization that high mechanical strength could be achieved effectively as a result of the well bonded powder contact surface during ECAP process. The SPD processing of powders is a viable method to achieve both fully density and nanostructured materials.

• 한국전기전자재료학회논문지
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• 제32권4호
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• pp.341-348
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• 2019

This paper reports the microstructure and electrochemical properties of Si-Al-Fe ternary amorphous alloys prepared by rapid solidification as an anode for lithium secondary batteries. The microstructure was analyzed using XRD and HR-TEM with EDS mapping. In accordance with DSC analysis, annealing was performed to crystallize the active nano-Si in the amorphous alloy. Thus, nano-Si forms (~80 nm) embedded in the matrix alloy, such as $Fe_2Al_3Si_3$, $FeSi_2$, and $Fe_{0.42}Si_{2.67}$, were successfully synthesized. The electrode based on the Si-Al-Fe ternary alloy delivered an initial discharge capacity of approximately $700mAh^{g-1}$, and exhibited a high Coulombic efficiency of 99.0~99.6% from the $2^{nd}$ to $70^{th}$ cycles.