• Composites Research
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• v.21 no.6
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• pp.15-22
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• 2008

Reversed plane bending fatigue tests were conducted on SiC particle aluminum composite. The initiation and growth behaviors of small surface fatigue cracks were continuously monitored by the replica technique and investigated in detail. The fatigue life of MMC is shorter than that of matrix because there exists interface debonding of SiC particles and matrix on the whole face of the notch part in the casting metal matrix composite(MMC). The coalescence of micro-cracks was observed in the tests conducted at high stress levels. Due to the coalescence, a higher crack growth rate of small cracks rather than those of long cracks was recognized in da/dn-$K_{max}$ relationship.

• Journal of Industrial Technology
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• v.19
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• pp.107-113
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• 1999

The microstructural evolution during mechanical alloying of elemental Fe and Si powders, average composition $Fe_{30}Si_{70}$ and $Fe_{50}Si_{50}$, has been investigated by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Differential scanning calorimetry (DSC). Mechanical alloying was performed by using a SPEX 8000 Mixer/Mill under argon atmosphere with/without hexane as a process control agent (PCA). In the presence of PCA, the milling process was dominated by fracture resulting in the decrease in particle size to about $1{\mu}m$. The structural development with milling time depended on the average composition of starting powders. The mixture of $Fe_{50}Si_{50}$ and $Fe_{30}Si_{70}$ resulted in the formation of FeSi(${\varepsilon}$ - phase) and $FeSi_2$(${\beta}$ - phase), respectively. In the case of $Fe_{33.3}Si_{66.7}$, a mixture and $FeSi_2({\beta})$ was formed. These results were discussed by considering the thermodynamics and kinetics concerning the milling process.

• Journal of Industrial Technology
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• v.5
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• pp.73-79
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• 1985

Thermodynamic calculation for the CVD of SiC from methyltrichlorosilane(MTS) was done in some range of deposition condition to identify optimum condition. The results show that the most considerable chemical species are chloride and chlorosilane for silicon source and methane and acetylene for carbon source. In order to yield single phase ${\beta}$-SiC it is believed that optimum temperature range is between 1500 and $1700^{\circ}k$. With increasing temperature, stable phase is changed from Si+SiC phase to C+SiC phase. It is believed because equilibrium concentration of silicon source decrease and equilibrium concentration of carbon source increases with increasing temperature.

• 정보화사회
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• s.184
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• pp.14-27
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• 2007

'오늘보다 더 나은 내일' 새해를 맞는 모든 이들의 바람이다. IT업계의 바람도 이와 크게 다르지 않다. 다행스러운 것은 올해가 작년보다 조금 나을 것 같다는 예측들이 많다는 것이다. '정보화사회'가 신년을 맞아 산업 부문별로 경기를 전망한 결과, 유선전화 시장을 제외하고는 대부분의 산업이 역동적으로 움직일 것으로 예상됐다. 모바일 서비스 시장은 3G중심으로 급속히 재편될 것으로 예상됐으며, 휴대폰 시장은 전년 대비 13% 성장할 것으로 전망됐다. IT서비스관리 시장도 작년 대비 50% 이상 급성장 할 것으로 전망됐으며, SI 시장도 비교적 호재가 많을 것으로 예상됐다. 유선, 초고속 인터넷, 모바일, SI, 네트워크, 보안, HW, SW 등 11개 산업분야의 2007년 시장전망을 분석 정리했다.

• 주류산업
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• v.19 no.1
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• pp.1-9
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• 1999

• Nuclear industry
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• v.26 no.7 s.281
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• pp.38-39
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• 2006

• 주류산업
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• v.23 no.3
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• pp.1-11
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• 2003

• 주류산업
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• v.21 no.4
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• pp.1-9
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• 2001

• Journal of the Korean Society of Industry Convergence
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• v.7 no.4
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• pp.349-354
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• 2004

The growth mode of the Si layers which were grown on Si(111) by using Ag as surfactant were investigated by intensity oscillations of the RHEED specular spot at the different temperatures. we found that the introduction of Ag as the surfactant alters the growth mode from a three-dimensional clustering mechanism to a two-dimensional layer-by-layer growth. In the growth of Si layers on Si(111) with a surfactant Ag, At $450^{\circ}C$, RHEED intensity oscillation was very stable and periodic from early stage of deposition to 32 ML. RHEED patterns during homoepitaxial growth at $450^{\circ}C$ was changed from $7{\times}7$ structure into ${\sqrt{3}}{\times}{\sqrt{3}}$ structures. Since the ${\sqrt{3}}{\times}{\sqrt{3}}$ structure include no stacking fault, the stacking fault layer seems to be reconstructed into normal stacking one at transition from the $7{\times}7$ structure to a ${\sqrt{3}}{\times}{\sqrt{3}}$ one. We also found that the number of the intensity oscillation of the specular spot for Si growth with a surfactant Ag was more than for Si growth without a surfactant. This result may be explained that the activation energy decrease for the surface diffusion of Si atoms due to segregation of the surfactant toward the growing surface.

• 정보산업연감
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• s.1995
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• pp.401-410
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• 1995