• 제목/요약/키워드: low temperature adhesion

검색결과 208건 처리시간 0.034초

Pure inorganic protective silica coating on stainless steel prepared at low heat treatment temperature

  • 황태진
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2010년도 춘계학술발표대회
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    • pp.6.2-6.2
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    • 2010
  • Stainless steel is widely known to have superior corrosion properties. However, in some harsh conditions it still suffers various kinds of corrosions such as galvanic corrosion, pitting corrosion, intergranular corrosion, chloride stress corrosion cracking, and etc. For the corrosion protection of stainless steel, the ceramic coatings such as protective silica film can be used. The sol-gel coating technique for the silica film has been extensively studied especially because of the cost effectiveness. It has been proved that silica can improve the oxidation and the acidic corrosion resistance of metal surface in a wide range of temperatures due to its high heat and chemical resistance. However, in the sol-gel coating process there used to engage a heat treatment at an elevated temperature like $500^{\circ}C{\sim}600^{\circ}C$ where cracks in the silica film would be formed because of the thermal expansion mismatch with the metal. The cracks and pores of the film would deteriorate the corrosion resistance. When the heat treatment temperature is reduced while keeping the adhesion and the density of the film, it could possibly give the enhanced corrosion resistance. In this respect, inorganic protective silica film was tried on the surface of stainless steel using a sol-gel chemical route where silica nanoparticles, tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) were used. Silica nanoparticles with different sizes were mixed and then the film was deposited on the stainless steel substrate. It was intended by mixing the small and the large particles at the same time a sufficient consolidation of the film is possible because of the high surface activity of the small nanoparticles and a modest silica film is obtained with a low temperature heat treatment at as low as $200^{\circ}C$. The prepared film showed enhanced adhesion when compared with a silica film without nanoparticle addition. The films also showed improved protect ability against corrosion.

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무연계 Ag 외부전극재의 열충격에 따른 열화특성과 고장해석 (Degradation and Failure Analysis of Lead-free Silver Electrodes with Thermal Cycling)

  • 김정우;윤동철;이희수;전민석;송준광
    • 한국전기전자재료학회논문지
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    • 제21권5호
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    • pp.434-439
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    • 2008
  • Silver pastes as the outer electrodes have been prepared using Pb-free glass frits with different content of $Bi_2O_3$ and the effects of glass composition on the degradation behaviors of the Ag electrodes were investigated using the change of adhesion between Ag electrode and alumina substrate with thermal cycle stress. Low adhesion and high surface resistance were observed in Ag electrode using glass frit with a $Bi_2O_3$ content of 60 wt%, owing to the open microstructure formed at the firing temperature of $600^{\circ}C$. When the $Bi_2O_3$ was increased to 80 wt% in the glass frit, the Ag electrodes had a dense microstructure with high adhesion and a low surface resistance. Delamination of the Ag electrodes was a major failure mode under thermal cycle stress and this was attributed to residual stress due to the thermal expansion mismatch between the Ag electrode and the alumina substrate.

저온균일침전법으로 제조된 TiO2 분말의 아크릴레진에서의 분산특성 및 광분해 효과 (Dispersion Properties and Photocatalytic Activities of TiO2 Powders Obtained by Homogeneous Precipitation Process at Low Temperature in a Acrylic Resin)

  • 우승희;김흥회;이창규
    • 한국분말재료학회지
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    • 제11권6호
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    • pp.503-509
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    • 2004
  • Dispersion stabilities and photocatalytic activities of rutile $TiO_{2}$ powders with unique nano-structure synthesized by homogeneous precipitation process at low temperature(HPPLT) have been investigated in the acrylic resin containing fluorostyrene in the range of 0~0.16 mole. Isoelectric point of $TiO_{2}$ in the acrylic resin placed in the neutral region whereas that of $TiO_{2}$ in the water placed in the acidic region, indicating that zeta potential and agglomeration of $TiO_{2}$ powder is strongly dependent on the pH and the type of solvent. To prepare an adhesion, an acrylic resin containing fluorostyrene was synthesized by a radical polymerization. The adhesion of coating layer was increased with increasing fluorostyrene's contents without changing the dispersion stabilities and degrading photocatalytic properties.

바이오복합재료 제조 공정시 제조온도 및 시간에 의한 영향 평가 (Evaluation of the Impact on Manufacturing Temperature and Time in the Production Process of Bio-composites)

  • 박상용;한규성;김희수;양한승;김현중
    • Journal of the Korean Wood Science and Technology
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    • 제33권1호통권129호
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    • pp.29-37
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    • 2005
  • 본 연구는 바이오복합재(bio-composites) 제조시 제조온도와 시간이 기질인 열가소성 고분자와 충전제인 왕겨분말에 미치는 영향을 평가하기 위하여 수행하였다. 제조온도가 왕겨분말에 미치는 영향에 대해 알아보기 위해 왕겨분말을 $220^{\circ}C$에서 10분부터 2시간 동안 처리한 후 열가소성 고분자인 polypropylene (PP)과 low-density polyethylene (LDPE)에 충전제로 첨가하여 바이오복합재를 제조한 후 기계적 성질을 측정하였다. $220^{\circ}C$에서 왕겨분말의 처리시간이 증가할수록 왕겨분말의 주요 구성성분이 열분해로 인하여 인장강도와 충격강도값이 감소하였다. 실제적인 제조온도에 의한 중량감소를 측정하기 위하여 열중량분석기(thermogravimetric analysis, TGA)를 이용하여 $220^{\circ}C$의 등온상태에서 2시간 동안 측정한 결과 열가소성고분자에서는 중량의 변화가 거의 발생하지 않았으며 충전제인 왕겨분말과 바이오복합재의 경우 시간이 증가할수록 열분해에 의한 중량감소량이 증가하는 것을 확인할 수 있었다. 그러므로 바이오복합재 제조시 높은 제조온도로 인한 물성의 저하를 방지하기 위해서는 적절한 온도와 제조시간을 결정하는 것이 중요하다고 볼 수 있다.

카르복시산을 포함하는 Grafted EPDM의 접착특성에 관한 연구 (Studies on Adhesion Properties of Grafted EPDM Containing Carboxylic Acid Group)

  • 김동호;윤유미;정일두;박찬영;배종우;오상택;김구니
    • 접착 및 계면
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    • 제13권1호
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    • pp.1-8
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    • 2012
  • EPDM에 카르복시산을 포함하는 아크릴 단량체인 methacrylic acid (MA)가 도입된 grafted EPDM을 합성하여 MA의 grafting ratio가 탄성체의 물성과 다른 고무와의 접착특성에 미치는 영향을 연구하였다. Grafted EPDM의 storage modulus는 특정온도까지는 sulfur로 가교한 EPDM vulcanizate보다 높게 유지되다가 온도가 더 높아지면 2차 결합력이 약해지면서 급격하게 감소되는 것이 관찰되었다. EPDM에 수소결합을 유도할 수 있는 반응기를 도입했을 때 grafted EPDM 분자들 간의 aggregate 형성과 그라프트된 MA의 결정성으로 인해 우수한 기계적 물성을 나타내었다. EPDM 자체는 극성이 낮고 다른 종류의 고무와 분자간 결합력이 약해서 접착이 제대로 이루어지지 않았으며 그라프트된 MA의 함량이 증가할수록 접착강도가 더 높아졌으며 MA의 grafting ratio가 10% 이상일 때에는 접착평가 시 고무시편이 부분적으로 파괴될 정도로 접착력이 우수하였다.

방수·방근시트와 옥상녹화 박스유닛 시스템의 일체화를 위한 전자기 유도가열 융착 고정구의 부착성능 (Adhesion Performance of Electromagnetic Induction Heating Pixture for the Integration with a Waterproof & Root Barrier Sheet and a Roof Green Unit System)

  • 오창원
    • 한국건축시공학회지
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    • 제18권5호
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    • pp.463-469
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    • 2018
  • 기존의 다층으로 구성되어 시공성이 낮은 옥상녹화 공법의 개선을 위해 개발한 방수 방근 시트 일체화 옥상녹화박스 유닛공법의 일체화를 위해 사용하는 전자기 유도가열방식의 금속 고정구와 콘 형상 고정구의 부착성능을 평가하기 위해 엔지니어링 PE, TPO, PVC 시트 등 3종류의 시트에 가열온도에 따른 부착성능 및 동일한 시험체로 냉열반복 후 부착성능을 측정하였다, 그 결과는 엔지니어링 PE시트에 부착한 고정구의 부착성능이 가장 우수하게 나타났으며, 금속고정구는 가열온도가 올라갈수록, 콘 형상 고정구는 가열온도가 낮을수록 우수한 부착성능을 보여주었고, 냉열 반복 후 부착시험 결과는 상온 부착시험 결과와 동일하게 나타났다. 기존의 양면 부틸테이프 고정방식의 콘 형상 고정구는 낮은 부착하중과 냉열반복에 의한 뚜렷한 성능저하가 발생하는데 비하여 전자기 유도가열방식의 고정구는 우수한 성능을 유지하였다.

Characteristics of MOCVD Cobalt on ALD Tantalum Nitride Layer Using $H_2/NH_3$ Gas as a Reactant

  • 박재형;한동석;문대용;윤돈규;박종완
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.377-377
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    • 2012
  • Microprocessor technology now relies on copper for most of its electrical interconnections. Because of the high diffusivity of copper, Atomic layer deposition (ALD) $TaN_x$ is used as a diffusion barrier to prevent copper diffusion into the Si or $SiO_2$. Another problem with copper is that it has weak adhesion to most materials. Strong adhesion to copper is an essential characteristic for the new barrier layer because copper films prepared by electroplating peel off easily in the damascene process. Thus adhesion-enhancing layer of cobalt is placed between the $TaN_x$ and the copper. Because, cobalt has strong adhesion to the copper layer and possible seedless electro-plating of copper. Until now, metal film has generally been deposited by physical vapor deposition. However, one draw-back of this method is poor step coverage in applications of ultralarge-scale integration metallization technology. Metal organic chemical vapor deposition (MOCVD) is a good approach to address this problem. In addition, the MOCVD method has several advantages, such as conformal coverage, uniform deposition over large substrate areas and less substrate damage. For this reasons, cobalt films have been studied using MOCVD and various metal-organic precursors. In this study, we used $C_{12}H_{10}O_6(Co)_2$ (dicobalt hexacarbonyl tert-butylacetylene, CCTBA) as a cobalt precursor because of its high vapor pressure and volatility, a liquid state and its excellent thermal stability under normal conditions. Furthermore, the cobalt film was also deposited at various $H_2/NH_3$ gas ratio(1, 1:1,2,6,8) producing pure cobalt thin films with excellent conformality. Compared to MOCVD cobalt using $H_2$ gas as a reactant, the cobalt thin film deposited by MOCVD using $H_2$ with $NH_3$ showed a low roughness, a low resistivity, and a low carbon impurity. It was found that Co/$TaN_x$ film can achieve a low resistivity of $90{\mu}{\Omega}-cm$, a low root-mean-square roughness of 0.97 nm at a growth temperature of $150^{\circ}C$ and a low carbon impurity of 4~6% carbon concentration.

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Substrate Temperature Effects on DC Sputtered Mo thin film

  • Ahn, Heejin;Lee, Dongchan;Um, Youngho
    • Applied Science and Convergence Technology
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    • 제26권1호
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    • pp.11-15
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    • 2017
  • To improve the adhesion of Mo thin film as a back contact material, a DC magnetron sputtering system was used to deposit in the form of a bi-layer on soda-lime glass. Films with low resistivity and good adhesion were obtained from this deposition, even though the two qualities were found be hard to obtain at the same time. The best Mo bi-layer showed a resistivity of $8.13{\times}10^{-4}{\Omega}{\cdot}cm$ at $500^{\circ}C$ and $3.0{\times}10^{-3}\;Torr$. The XRD measurements showed that the crystallites of the films were mainly oriented in the (110) direction, the FE-SEM images revealed that the resistivity of the Mo films decreased with increasing substrate temperature, which temperature reduction is accompanied by an increase of the grain size. These experimental results were analyzed using the Fuchs-Sondheimer theory. Our Mo bi-layer film with better crystallinity and lower resistivity can be suitably used as a back-contact layer for CIGS solar cells.

Low Temperature Processes of Poly-Si TFT Backplane for Flexible AM-OLEDs

  • Hong, Wan-Shick;Lee, Sung-Hyun;Cho, Chul-Lae;Lee, Kyung-Eun;Kim, Sae-Bum;Kim, Jong-Man;Kwon, Jang-Yeon;Noguchi, Takashi
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.785-789
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    • 2005
  • Low temperature deposition of silicon and silicon nitride films by catalytic CVD technique was studied for application to thin film transistors on plastic substrates for flexible AMOLEDs. The substrate temperature initially held at room temperature, and was controlled successfully below $150^{\circ}C$ during the entire deposition process. Amorphous silicon films having good adhesion, good surface morphology and sufficiently low content of atomic hydrogen were obtained and could be successfully crystallized using excimer laser without a prior dehydrogenation step. $SiN_x$ films showed a good refractive index, a high deposition rate, a moderate breakdown field and a dielectric constant. The Cat-CVD silicon and silicon nitride films can be good candidates for fabricating thin films transistors on plastic substrates to drive active-matrix organic light emitting display.

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핫 멜트 접착제로 사용되는 비 결정성 올레핀 수지/석유수지 블렌드의 열적 성질 및 접착성에 관한 연구 (Study on the Thermal Properties and Adhesion Strength of Amorphous Polyalphaolefins/Petroleum Resin Blonds as a Hot Melt Adhesive)

  • 홍인오;김환기;강호종
    • 폴리머
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    • 제24권4호
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    • pp.513-519
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    • 2000
  • 핫 멜트 접착제의 점착제로 사용되고 있는 석유수지를 비 결정성 올레핀 수지에 블렌딩하였을 때 점착제가 비 결정성 올레핀 수지의 열적 특성 및 결정화거동에 미치는 영향과 이에 따른 접착특성 변화에 대하여 살펴보았다. 점착제로 사용된 석유수지는 비 결정성 올레핀 수지의 용융온도를 저하시키고 이러한 현상은 에틸렌 함량이 상대적으로 많은 비 결정성 올레핀 수지에서 두드러지며, aromatic 수지인 $C_{9}$ 석유수지보다는 aliphatic 수지인 $C_{5}$ 석유수지를 사용할 때 그 감소의 폭이 큼을 알 수 있었다. 아울러 석유수지의 블렌딩에 의하여, 특히 aromatic 수지인 $C_{9}$을 첨가하였을 경우, 비 결정성 수지의 에틸렌 함량이 적을수록 결정화도가 현저히 감소함을 확인할 수 있었다. 점착제의 조성비가 50% 정도에서 가장 우수한 접착력을 확인할 수 있었으며, 에틸렌 함량에 관계없이 $C_{5}$ 석유수지의 첨가시 접착력이 현저히 향상됨을 알 수 있었다. 에틸렌 함량이 적은 비결정성 올레핀/석유수지 핫 멜트에서는 점착제로 인하여 발현된 결정화도 감소에 의하여 접착특성이 증가됨을 알 수 있었다.

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