• 제목/요약/키워드: polycrystalline

검색결과 1,290건 처리시간 0.031초

다결정 다이아몬드 공구를 이용한 Al-Mg계 합금의 미소선삭가공특성에 관한 연구 (A Study on the Micro Turning Machinability of A1-Mg Alloy Using Polycrystalline Diamond Tool)

  • 황준;남궁석
    • 한국정밀공학회지
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    • 제13권5호
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    • pp.122-130
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    • 1996
  • In this study, machinability of some aluminum-magnesium alloy are experimentally investigated using polycrystalline diamond tool with turning, and evaluated some independent cutting variables affected micrometal cutting characteristics as cutting force, specific cutting resistance, shear angles. To know the effect of cutting parameters of single point diamond machining, experiments were performed to measure cutting forces for high speed turning of aluminum alloy 6061-T6, SM45C and FC20 with poly- crystalline diamond and coated cemented carbide tool. Independent cutting variables were changed to a variety of cutting speed, feed rate, rake angles, material properties of workpiece and tool. Futhermore. Some useful informations are obtained in this study can guide micro metal cutting of aluminum alloy with diamond tool.

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폴리다이메틸실록산 코팅을 통한 다결정성 UiO-66 분리막의 비선택적 결정립계 결함 캡핑 (Capping Intercrystalline Defects of Polycrystalline UiO-66 Membranes by Polydimethylsiloxane Coating)

  • 김익지;권혁택
    • 청정기술
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    • 제29권1호
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    • pp.71-75
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    • 2023
  • 다공성 결정물질(예: 금속유기골격체(Metal-Organic Framework, MOF), 제올라이트(zeolite))로 만들어진 다결정성 분리막의 선택도는 일반적으로 크기가 1 nm 혹은 그 이상으로 알려진 비선택적 결정 간 결함, 즉 결정립계의 존재 때문에 저하된다. 본 논문에서는 다결정성 MOF 분리막 위에 폴리다이메틸실록산(polydimethylsiloxane, PDMS)의 코팅이 결정립계를 캡핑하여 분리막의 선택도를 향상시키는데 효과적임을 증명하였다. 제안된 개념을 증명하기 위해서 in-situ 용매열 합성법을 통해 제조된 지르코늄 기반의 MOF의 일종인 UiO-66 분리막 위에 PDMS를 코팅한 후, 코팅 전후의 성능변화를 관찰하였다. PDMS 코팅 후 UiO-66 분리막의 CO2/N2 단일 기체 분리 선택도는 6에서 14로 증가하였고, 동시에 CO2 투과도는 5700 GPU에서 33 GPU로 감소하였다. 선택도의 증가는 PDMS 코팅이 결정립계 결함을 효과적으로 메웠음을 의미하며, 동반된 투과도의 감소는 PDMS 코팅이 결함을 메우는 동시에 분리막 위에 연속적인 층을 형성하여 추가된 투과 저항에서 비롯되었다고 판단된다.

스트레스 인가에 의한 다결정 실리콘 박막 트랜지스터의 열화 특성 (Degradation of Polycrystalline Silicon Thin Film Transistor by Inducing Stress)

  • 백도현;이용재
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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    • pp.322-325
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    • 2000
  • N-channel poly-Si TFT, Processed by Solid Phase Crystalline(SPC) on a glass substrate, has been investigated by measuring its electrical properties before and after electrical stressing. It is observed that the threshold voltage shift due to electrical stress varies with various stress conditions. Threshold voltages measured in 1.5$\mu\textrm{m}$ and 3$\mu\textrm{m}$ poly-Si TFTs are 3.3V, 3.V respectively. With the threshold voltage shia the degradation of transconductance(G$\_$m/) and subthreshold swing(S) is also observed.

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Progess in Fabrication Technologies of Polycrystalline Silicon Thin Film Transistors at Low Temperatures

  • Sameshima, T.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.129-134
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    • 2004
  • The development of fabrication processes of polycrystalline-silicon-thin-film transistors (poly-Si TFTs) at low temperatures is reviewed. Rapid crystallization through laser-induced melt-regrowth has an advantage of formation of crystalline silicon films at a low thermal budget. Solid phase crystallization techniques have also been improved for low temperature processing. Passivation of $SiO_2$/Si interface and grain boundaries is important to achieve high carrier transport properties. Oxygen plasma and $H_2O$ vapor heat treatments are proposed for effective reduction of the density of defect states. TFTs with high performance is reported.

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$N^+-P/P^+$ 다결정 실리콘 태양 전지의 제작 및 특성 (Fabrication and Characteristics of $N^+-P/P^+$ Polycrystalline Silicon Solar Cell)

  • 정호선
    • 대한전자공학회논문지
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    • 제19권5호
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    • pp.38-42
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    • 1982
  • 비저항은 3∼60hm-cm이고 두께는 350∼400μm인 다결정 실리콘을 사용하여 n+-P/P+태양 전지를 제작하였다. 이 전지에 대한 소수 반송자의 수명은 Nd:YAG laser로 측정되었으며 100∼150ns 이었다. 전지의 변환 효율은 AM 1에서 4%로 측정 되었다.

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비수용액에서의 다결정 알루미나 섬유질의 개발에 관한 연구 (A Study on the Development of Polycrystalline Alumina Fibers in the Non-aqueous System)

  • 정형진;김구대
    • 한국세라믹학회지
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    • 제25권5호
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    • pp.425-430
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    • 1988
  • In this study, aluminum sec-butoxide, aluminum iso-propoxide were mixed with alcohol such as, secbutanol, iso-propanol. And then Acetyl Acetone, water were added to make Acetyl bond and OH bond. After that, Polymeric alumina sol was synthesized from catalysis reaction with strong acid typically HCl. These alumina soil was dried at 8$0^{\circ}C$~9$0^{\circ}C$ to have a optmum viscosty for spinning, spinned at spinner, and then sintered to make polycrystalline alumina fiber.

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Performance of Thin Film Transistors Having an As-Deposited Polycrystalline Silicon Channel Layer

  • Hong, Wan-Shick;Cho, Hyun-Joon;Kim, Tae-Hwan;Lee, Kyung-Min
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1266-1269
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    • 2007
  • Polycrystalline silicon (poly-Si) films were prepared directly on plastic substrates at a low (< $200^{\circ}C$) by using Catalytic Chemical Vapor Deposition (Cat-CVD) technique without subsequent annealing steps. Surface roughness of the poly-Si layer and the density of the gate dielectric layer were found to be influential to the TFT performance.

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Low-temperature polycrystalline silicon level shifter using capacitive coupling for low-power operation

  • Chung, Hoon-Ju;Sin, Yong-Won;Cho, Bong-Rae
    • Journal of Information Display
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    • 제11권1호
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    • pp.21-23
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    • 2010
  • A new level shifter using low-temperature polycrystalline silicon (poly-Si) thin-film transistors (TFTs) for low-power applications is proposed. The proposed level shifter uses a capacitive-coupling effect and can reduce the power consumption owing to its no-short-circuit current. Its power saving over the conventional level shifter is 72% for a 3.3 V input and a 10 V output.

Microstructural study of polycrystalline films prepared by Ni vapor induced crystallization

  • Ahn, Kyung-Min;Lee, Kye-Ung;Ahn, Byung-Tae
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.715-717
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    • 2006
  • $NiCl_2$ vapor was introduced into conventional furnace to conduct vapor-induced crystallization (VIC) process. We made the metal chloride atmosphere by sublimating the $NiCl_2$ compound. The $NiCl_2$ atmosphere enhanced the crystallization of amorphous silicon thin films. As the result, polycrystalline Si film with large grain size and low metal contamination has been obtained.

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집합조직의 발전을 반영하는 다결정재의 정상상태성형공정해석 (Finite Element Analysis for Steady State Forming Process of Polycrystalline Metal Including Texture Development)

  • 김응주;이용신
    • 소성∙가공
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    • 제5권4호
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    • pp.297-304
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    • 1996
  • A process model is formulated considering the effect of crystallographic texture developed in forming process. The deformation induced plastic anisotropy can be predicted by capturing the evolution of texture during large deformation in the polycrystalline aggregate. The anisotropic stiffness matrix for the aggregate is derived and implemented in Eulerian finite element code using a Consistent Penalty method. As an application the evolution of texture in rolling drawing and extrusion processes are simulated. The numerical results show good agreements with report-ed experimental textures.

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