• 한국해양공학회지
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• 제22권5호
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• pp.106-111
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• 2008

In this paper, study about property evaluation for the metal matrix composites fabricated by low pressure infiltration process. Aluminum alloy composite which is reinforced by Metal fiber preform was fabricated by low pressure casting process. Infiltration condition was changed the pressure infiltration time of 1 sec, 2 sec and 5 sec under a constant pressure of 0.4 MPa. The molten alloy completely infiltrated the FeCrSi metal perform regardless of the increase in the pressure acceleration time. The the porosity in the FeCrSi/AC8A composite was investigated. The porosity was reduced as the pressure acceleration time as shorter. The FeCrSi/AC8A composite was investigated the wear test for to know the relationship between Porosity and wear resistance. FeCrSi/AC8A composite at pressure acceleration time of 1sec is shown excellent wear resistance.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.262-267
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• 2007

In this paper, we study about wear properties for the metal matrix composites fabricated by low pressure infiltration process. Metal fiber preform reinforced aluminum alloy composite were fabricated by low pressure casting process under 0.4MPa. Infiltration condition was changed the pressure infiltration time of 1 s, 2 s and 5 s under a constant pressure of 0.4MPa. The molten alloy completely infiltrated the FeCrSi metal perform regardless of the increase in the pressure acceleration time. However, the infiltration time at the pressure acceleration time of 1s was shorter than at the pressure acceleration time of 2s or 5s. The FeCrSi/A366.0 composite was investigated the porosity. The porosity is reducing as the pressure acceleration time compared with the pressure acceleration time of 2s and 5s. The FeCrSi/A366.0 composites were investigated the wear resistance. FeCrSi/A366.0 composite at pressure acceleration time of 1s has excellent wear resistance.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.122.1-122.1
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• 2005

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 1999년도 추계학술발표대회 논문집
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• pp.83-87
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• 1999

The fabrication process and thermal properties of 50~71vol% SiCp/Al metal matrix composites (MMCs) were investigated. The 50~71vol% SiCp/Al MMCs fabricated by pressure infiltration casting process showed that thermal conductivities were 118~170W/mK and coefficient of thermal expansion (CTE) were 9.5~$6.5{\times}10^{-6}/K$. Specially, the thermal conductivity and CTE of 71vol%SiCp/Al MMCs were 115~156W/mK and 6~$7{\times}10^{-6}/K$. respectively, which showed a improved themal properties than the conventional electronic packaging materials such as ceramics and metals.

• 한국재료학회지
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• 제4권3호
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• pp.259-267
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• 1994

프로판($C_3H_8$)을 반응가스로 사용하여 등온 저압화학기상침투법(low-pressure chemical vapor infiltration)으로 탄소/탄소 복합재료를 치밀화 할 때 반응온도, 반응가스농도, 가스유량, 반응압력 등의 제조공정변수들이 치밀화에 미치는 영향을 알아보기 위하여 실험계획법(Rdbust design method)에 의한 실험을 행하였다. 1회의 등온 저압화학기상침투 실험으로 탄소/탄소 복합재료의 부피 밀도와 표면과 내부의 부피 밀도의 차이를 특성치(characteristic value)로 한 실험계획법의 분산분석(analysis of variance)에 의하면 반응온도, 반응가스농도, 가스유량 등의 제고공정변수가 치밀화에 기여도가 높으며, 반응압력의 기여도와 제조공정변수들의 교호작용(interaction)에 의한 기여도는 낮은 것으로 나타났다. 반응온도가 $1100^{\circ}C$, 반응가스농도가 100% $C_3H_8$, 가스유량이 100 SCCM, 반응압력이 5torr인 조건에서 탄소/탄소 복합재료는 가장 높은 부피 밀도값을 나타내었으나 시편의 표면과 내부의 부피 밀도 차이값은 컸다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.190-194
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• 2000

The fabrication process and thermal properties of 50∼76vo1% SiCp/Al metal matrix composites (MMCs) were investigated. The 50∼76vo1% SiCp/Al MMCs fabricated by pressure infiltration casting process showed that thermal conductivities were 85∼170W/mK and coefficient of thermal expansion (CTE) were ranged 10∼6ppm/K. Specially, the thermal conductivity and CTE of 71vo1%SiCp/Al MMCs were ranged l15∼156W/mK and 6∼7ppm/K, respectively, which showed a improved thermal properties than the conventional electronic packaging materials such as ceramics and metals.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 추계학술발표대회 논문집
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• pp.50-53
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• 2003

Carbon nannofiber reinforced Cu matrix composite has potential applications for electrically conducting materials having high strength and electrical conductivity. In this study, we have developed fabrication technology of the nanocomposites using a liquid pressing process. The process is to use the low pressure for infiltration of Cu melt into carbon nanofiber mat as the Cu melt is pressurized directly. The minimum pressure required for infiltration was calculated from force balance equation, permeability measurement and compaction behavior of carbon nanofiber. Also, the melting temperature and the holding time have been optimized.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.250-253
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• 2004

Emphasis has been placed on thin plate fabrication of plain woven carbon fabric reinforced Al matrix composites using liquid pressing process. The composite has potential applications for PDP rear plate. The process is to use the low pressure for infiltration of Al melt into plain woven carbon fabric as the Al melt is pressurized directly. The minimum pressure required for the infiltration was calculated from force balance equation, permeability measurements and compaction behavior of carbon fiber. Also, the melting temperature and the holding time have been optimized. In order to measure coefficient of thermal expansion (CTE) of the composites, the thermal strain measurement using strain gage was performed and the thermal conductivity of the composites was measured using laser flash method. The constituent materials of the composite are PAN type carbon fibers as reinforcements and 6061 Al alloys as matrices.

• Journal of Plant Biotechnology
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• 제31권4호
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• pp.279-283
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• 2004

백합 (Lilium longiflorum cv. Georgia) 화분의 생장과 agro-infiltration에 의한 일시발현에 대한 물리적, 화학적, 생물적 요인의 영향을 분석하였다 화분을 배지에 섞기 위한 물리적 과정이나 agro-infiltration을 위한 진공작업과정은 정상적 화분생장을 위하여 최소화되는 것이 바람직한 것으로 나타났다. 비교적 넓은 범위에서의 온도 (19 to 27$^{\circ}C$)나 pH(5.0 to 8.0)에서 화분의 생장이 유사하게 진행되었으며 화학적 요인으로서의 cefotaxime (300mg/L), acetosyringone (800 $\mu$M), syringealdehyde (800 $\mu$M) 등의 처리는 화분의 생장에 영향을 나타내지 않았다. 그러나 kanamycin의 경우 매우 심한 생장저해현상을 보였는데 25mg/L의 농도에서도 저해현상을 보이는 경우도 있었다. GUS유전자의 화분발현시 acetosyringone(200-400$\mu$M)의 처리에 의하여 그 효율이 약간 향상되는 것으로 나타났으나 syringealdehyde의 경우에는 효과가 없었다. 짧은 시간 내의 agro-infiltration과정과 이어서 18 hr의 화분 및 박테리아의 동시배양으로서도 acetosyringone의 첨가에 상관없이 화분에서의 GUS 일시 발현결과를 얻을 수 있었다.

• 한국산업융합학회 논문집
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• 제21권1호
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• pp.29-36
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• 2018

Low pressure casting process for unidirectional carbon fiber reinforced aluminum (UD-CF/Al) composites which is an infiltration route of molten Al into porous UD-CF preform has been a cost-effective way to obtain metal matrix composites (MMCs) but, easy to cause non-uniform fiber distribution as CF clustering. Such clustered CFs have been a problem to decrease the density and thermal conductivity (TC) of composites, due to the existence of pores in the clustered area. To obtain high thermal performance composites for heat-sink application, the relationship between fiber distribution and porosity has to be clearly investigated. In this study, the CF distribution was evaluated with quantification approach by using two-dimensional spatial distribution method as local number 2-dimension (LN2D) analysis. Note that the CFs distribution in composites sensitively changed by sizes of Cu bridging particles between the CFs added in the UD-CF preform fabrication stage, and influenced on only $LN2D_{var}$ values.