• 제목/요약/키워드: Aluminum substrate

검색결과 366건 처리시간 0.024초

분사주조 성형체의 기공형성에 대한 기판재료의 영향 (Effects of Substrate Materials on the Porosity Formation of Spary Cast Deposit)

  • 김동규
    • 한국주조공학회지
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    • 제13권5호
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    • pp.476-483
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    • 1993
  • The influence of substrate materials on the degree of basal porosity during spray casting process has been investigated. Different conditions of droplet spreading on the substrate were induced by varying the substrate material. Flat sections of cast iron and aluminum have been spray deposited via spray casting process onto an aluminum substrate, a low carbon steel substrate, and an alumina based refractory substrate. Results for cast iron and aluminum sprayed onto the aluminum substrate showed significant improvements in the surface condition and degree of basal porosity with evidence of substrate deformation that round pits ranging from $5{\mu}m$ to $20{\mu}m$ in diameter are distributed on the surface of aluminum substrate. The lowest level of porosity was developed in alumina based refractory material. Several mechanisms for porosity formation were discussed with droplet impact pressure and droplet spreading. Adopting a spray cutting mechanism for removing the periphery of spray cone, porosity level was remarkably decreased.

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Orientation Dependent Directed Etching of Aluminum

  • Lee, Dong Nyung;Seo, Jong Hyun
    • Corrosion Science and Technology
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    • 제8권3호
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    • pp.93-102
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    • 2009
  • The direct-current electroetching of high purity aluminum in hot aqueous-chloride solution produces a high density of micrometer-wide tunnels whose walls are made up of the {100} planes and penetrate aluminum in the <100> directions at rates of micrometer per second. In the process of the alternating-current pitting of aluminum, cathodic polarization plays an important role in the nucleation and growth of the pits during the subsequent polarization. The direct-current tunnel etching and alternating-current etching of aluminum are basically related to the formation of poorly crystallized or amorphous passive films. If the passive film forms on the wall, a natural misfit exists between the film and the aluminum substrate, which in turn gives rise to stress in both the film and the substrate. Even though the amorphous films do not have directed properties, their stresses are influenced by the substrate orientation. The films on elastically soft substrate are likely to be less stressed and more stable than those on elastically hard substrate. The hardest and softest planes of aluminum are the {111} and {100} planes, respectively. Therefore, the films on the {111} substrates are most likely to be attacked, and those on the {100} substrates are least likely to be attacked. For the tunnel etching, it follows that the tunnel walls tend to consist of the {100} planes. Meanwhile, the tunnel tip, where active corrosion takes place, tend to be made of four closely packed {111} planes in order to minimize the surface energy, which gives rise to the <100> tunnel etching.

고주파 유도가열을 통한 알루미늄 기판재위 Ni-Al계 금속간화합물의 연소합성코팅에 관한 연구 (A Study for Ni-Al based Intermetallics Coating onto Aluminum Substrate by Induction Heating)

  • 이한영
    • Tribology and Lubricants
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    • 제28권2호
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    • pp.56-61
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    • 2012
  • In order to investigate the possibility of Ni-Al based intermetallics coating onto aluminum substrate, the coating process for induction heating has been evaluated by microscopically analyzing the intermetallic layers coated at temperatures lower than the melting temperature of aluminum. The coating layers were divided into two parts with different microstructure along the depth. Hard $NiAl_3$ layer was found at lower parts of the coatings near the interface with aluminum substrate. This layer was formed by the diffusion of aluminum atoms from the substrate into the coating layer across the interface during the induction heating. Meanwhile, at the upper parts of the coating near the surface, a large amount of un-reacted Ni was still remained and surrounded by several Ni-Al based intermetallic compounds, such as $Ni_3Al$, NiAl and $Ni_2Al_3$ formed by the lattice diffusion.

알루미늄 양극산화를 사용한 DRAM 패키지 기판 (DRAM Package Substrate Using Aluminum Anodization)

  • 김문정
    • 대한전자공학회논문지SD
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    • 제47권4호
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    • pp.69-74
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    • 2010
  • 알루미늄 양극산화(aluminum anodization)의 선택적인 적용을 통하여 DRAM 소자를 위한 새로운 패키지 기판을 제작하였다. 에폭시 계열의 코어(core)와 구리의 적층 형태로 제작되는 일반적인 패키지 기판과는 달리 제안된 패키지 기판은 아래층 알루미늄(aluminum), 중간층 알루미나(alumina, $Al_2O_3$) 그리고 위층 구리(copper)로 구성된다. 알루미늄 기판에 양극산화 공정을 수행함으로써 두꺼운 알루미나를 얻을 수 있으며 이를 패키지 기판의 유전체로 사용할 수 있다. 알루미나층 위에 구리 패턴을 배치함으로써 새로운 2층 금속 구조의 패키지 기판을 완성하게 된다. 또한 알루미늄 양극산화를 선택적인 영역에만 적용하여 내부가 완전히 채워져 있는 비아(via) 구조를 구현할 수 있다. 패키지 설계 시에 비아 인 패드(via in pad) 구조를 적용하여 본딩 패드(bonding pad) 및 볼 패드(ball pad) 상에 비아를 배치하였다. 상기 비아 인 패드 배치 및 2층 금속 구조로 인해 패키지 기판의 배선 설계가 보다 수월해지고 설계 자유도가 향상된다. 새로운 패키지 기판의 주요 설계인자를 분석하고 최적화하기 위하여 테스트 패턴의 2차원 전자기장 시뮬레이션 및 S-파라미터 측정을 진행하였다. 이러한 설계인자를 바탕으로 모든 신호 배선은 우수한 신호 전송을 얻기 위해서 $50{\Omega}$의 특성 임피던스를 가지는 coplanar waveguide(CPW) 및 microstrip 기반의 전송선 구조로 설계되었다. 본 논문에서는 패키지 기판 구조, 설계 방식, 제작 공정 및 측정 등을 포함하여 양극산화 알루미늄 패키지 기판의 특성과 성능을 분석하였다.

알루미늄 순도 및 표면처리가 나노기공의 형성에 미치는 영향 (Effects of Aluminum purity and surface condition for fabricate Nano-sized Porous using Anodic Oxidation)

  • 이병욱;이재홍;장석원;김창교
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 C
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    • pp.1573-1575
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    • 2004
  • An alumina membrane with nano-sized pores was fabricated by anodic oxidation. The shape and structure of the pore on alumina membrane were changed according to the roughness of aluminum surface. The shape and structure of the nano-sized pre were investigated according to purity of aluminum substrate for the anodization process. The aluminum substrates with 99.5% and 99.999% purities were used. The aluminum substrate(99.5%) was anodized after the processes of pressing, mechanical polishing, chemical polishing, and electrochemical polishing. The nano-sized pores with the pore size of 50 - 100nm, the cell size of 20-50nm and the thickness of $10{\mu}m{\sim}45{\mu}m$ were obtained. Even though the electrochemical polishing was used for the aluminum substrate (99.999%), the same characteristics as the aluminum substrate (99.5%) was obtained. The alumina membrane prepared by anodization for 5 min using fixed voltage method shows the pore with irregular shape. The pore shape was changed to regular shape after pore widening process.

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Al 소지상에 무전해 Ni도금시 응력 변화 (The Change in Residual Stress of Electroless Nickel Deposits on Aluminum Substrate)

  • 권진수;최순돈
    • 한국표면공학회지
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    • 제29권2호
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    • pp.100-108
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    • 1996
  • The internal stress of acidic electroless nickel deposits on zincated aluminum was determined by spiral contractometer. Several plating conditions such as inhibitor and complexing agent concentrations and pH affecting the internal stress were studied. The resulting intrinsic stress contribution to the total stress was discussed in terms of phosphorous content of the deposit, solution pH, and surface morphology. However, the most important was found to be thermal stress for the total stress of Al substrate, because of high thermal expansion coefficient of the aluminum substrate.

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알루미늄 기판 위 반응합성 Coating 된 Ni-Al계 금속간화합물의 미끄럼마모 특성 해석 (Sliding Wear Properties of Ni-Al based Intermetallics Layer coated on Aluminum through Reaction Synthesis Process)

  • 이한영
    • Tribology and Lubricants
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    • 제34권2호
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    • pp.67-73
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    • 2018
  • Ni-Al intermetallic coating technology is an available method for the strengthening of aluminum substrate. In this study, Ni-Al intermetallics were coated on an aluminum substrate through a reaction synthesis process at a temperature lower than melting point of aluminum. And the sliding wear properties of the coatings have been investigated to verify their usability and compared the wear properties with those of a cast Al-12.5%Si alloy and an anodizing layer on aluminum. Results show that the wear rate of the coating layer greatly increased at 1 m/s and 1.5 m/s when compared with that of the cast Al-12.5%Si alloy. Much pitting damages were observed on the worn surfaces at these sliding speeds, unlike at other sliding speeds. The wear of the intermetallic coating layer at these sliding speeds seems to be increased by pitting as a consequence of adhesion. In contrast, wear of the coating layer at other speeds hardly occurs, regardless of wear periods. Nevertheless, the wear properties of the intermetallic coating layer on the aluminum substrate through the reaction synthesis process are more stable than those of anodized aluminum and are superior to those of the cast Al-12.5%Si alloy in a steady-state wear period.

알루미늄 주물 위 용탕열을 이용한 N-Al계 금속간화합물의 연소합성 코팅 (Ni-Al Based Intermetallics Coating Through SHS using the Heat of Molten Aluminum)

  • 이한영;조용재
    • 한국주조공학회지
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    • 제31권2호
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    • pp.83-86
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    • 2011
  • Ni-Al based intermetallic compounds of self-propagating high-temperature synthesis (SHS) by the heat of molten aluminum and been coated on the aluminum casting alloy. The effects of the pouring temperature in casting and the thickness of casting substrate on SHS of the coating layer have been investigated. The experimental result showed that the reaction of the coating layer was activated with increasing the pouring temperature in casting and the thickness of casting substrate. However, the aluminum substrate was re-melted by the heat of formation for intermetallic compounds. Then, it was considered that some mechanical or thermal treatments for elemental powder mixtures were required to control the heat of formation for intermetallic compounds in advance.

알루미늄 양극산화를 사용한 LED COB 패키지 (ED COB Package Using Aluminum Anodization)

  • 김문정
    • 한국산학기술학회논문지
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    • 제13권10호
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    • pp.4757-4761
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    • 2012
  • 알루미늄 기판 및 양극산화 공정을 사용하여 LED Chip on Board(COB) 패키지를 제작하였다. 선택적 양극산화 공정을 적용하여 알루미늄 기판 상에 알루미나를 형성하고 이를 COB 패키지 절연층으로 사용하였으며, 비아홀 내부가 충진된 구조의 Thermal Via를 구현하였다. 패키지 기판 종류에 따른 열저항 및 발광효율 변화를 파악하기 위해 알루미늄 기판과 알루미나 기판을 제작하고 이를 각각 비교 분석하였다. Thermal Via가 적용된 알루미늄 기판이 51%의 열저항 개선 및 14%의 발광효율 향상 특성을 보여주었다. 이러한 결과는 선택적 양극산화 공정 및 Thermal Via 구조적용으로 COB 패키지의 방열 특성이 향상되었음을 의미한다. 또한 동일한 전력 소모시 LED 칩 개수에 따른 COB 패키지의 열저항 및 발광효율 변화를 분석함으로써 다수 칩의 효율적인 배치가 열저항 및 발광효율을 증가시킬 수 있음을 확인하였다.

화학증착 알루미늄 박막의 표면 상태 개선에 관한 연구 (A study on the Improvement of Surface Topography in CVD Aluminum Thin Films)

  • 김영성;이경일;주승기
    • 한국표면공학회지
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    • 제26권3호
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    • pp.115-120
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    • 1993
  • Aluminum thin films were deposited on the silicon substrate by the pyrolysis of TrilsoButylAluminum (TIBA) in a cold wall LPCVD reactor. The effect of substrate on the surface topograply and the decomposition reaction was investigated. The activation energy for the decomposition of TIBA was turned out to be 1 eV from the Arrhenious plot. The surface topography of the CVD aluminum could be improved by the application of thin metal film, which was in-situ deposited on the silicon prior to CVD process.

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