• Title/Summary/Keyword: Metallic Plate

검색결과 211건 처리시간 0.029초

핀-핀 형 전극의 전기-수력학 프린팅에서 전극 직경이 미세 세라믹 패턴 형성에 미치는 영향 (Effect of Electrode Diameter on Pine Ceramic Pattern Formed by Using Pin-To-Pin Type Electro-Hydrodynamic Printing)

  • 이대영;유재훈;류태우;황정호;김용준
    • 정보저장시스템학회논문집
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    • 제1권1호
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    • pp.108-114
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    • 2005
  • The generation of fine relics of suspensions is a significant interest as it holds the key to the fabrication of electronic devices. These processes offer opportunities for miniaturization of multilayer circuits, for production of functionally graded materials, ordered composites and far small complex-shaped components. Some novel printing methods of depositing ceramic and metal droplets were suggested in recent years. In an electro-hydrodynamic printing, the metallic capillary nozzle can be raised to several kilovolts with respect to the infinite ground plate or pin-type electrode positioned a few millimeters from the nozzle tip. Depending on the electrical and physical properties of the liquid, for a given geometry, it Is possible to generate droplets in any one of three modes, dripping, cone-jet and multi-jet. In this experiment, an alumina suspension flowing through a nozzle was subjected to electro-hydrodynamic printing using pin-type electrodes in the cone-jet mode at different applied voltages. The pin-type electrodes of 1, 100, 1000${\mu}m$ in diameter were used to form fine ceramic patterns onto the substrates. Various feature sizes with applied voltages and electrode diameters were measured. The feature sizes increased with the electrode diameter and applied voltages. The feature size was as fine as $30 {\mu}m$.

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롤빔에 카본플레이트를 보강한 강재의 일체적거동 및 강성보강효과 (Test on the strengthening effects and behavior of Roll beam with Stiffened carbon-plate)

  • Sung, IkHyun
    • 한국재난정보학회 논문집
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    • 제9권4호
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    • pp.392-399
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    • 2013
  • 본 연구에서는 기존구조물에 대한 보수와 복구에 보강을 위하여 복합재료의 사용이 증가하고 있는 상황에서 방재의 개념에도 부합하는 탄소섬유보강재를 이용하여 기존금속재와 접합(접착방식)을 통한 강도증진효과를 연구하였다. 특히 실험을 통하여 강-탄소섬유보강재로 이루어진 복합재 거동을 파악하였으며 여기에 적절한 시험을 위한 새로운 형태의 시험편을 제작하였다. 접합재로 레진을 도포하는 방법을 달리하고 거동을 비교하기 위하여 표면처리가 다른 시험편을 각각 고려하여 시험한 결과 강성보강효과는 물론 일체거동의 특성이 잘 나타남을 알 수 있었다.

연료전지 분리판의 마이크로 채널 제작을 위한 가변성형공정의 실험적 및 수치적 연구 (Experimental and Numerical Analyses of Flexible Forming Process for Micro Channel Arrays of Fuel Cell Bipolar Plates)

  • 김홍석;심재민
    • 소성∙가공
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    • 제21권8호
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    • pp.499-505
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    • 2012
  • The fuel cell is a very promising power generation system combining the benefits of extremely low emissions, high efficiency, ease of maintenance and durability. In order to promote the commercialization of fuel cells, a flexible forming process, in which a hyper-elastic rubber is adopted as a medium to transmit forming pressure, is suggested as an efficient and cost effective manufacturing method for fuel cell bipolar plates. In this study, the ability of this flexible forming process to produce the micro channel arrays on metallic bipolar plates was first demonstrated experimentally. Then, a finite element (FE) model was built and validated through comparisons between simulated and experimental results. The effects of key process parameters on the forming performance such as applied load and punch velocity were investigated. As a result, appropriate process parameter values allowing high dimensional accuracy without failure were suggested.

Microstructure and Corrosion Properties of TiNX Thin Films Prepared by High Density Plasma Reactive Magnetron Sputtering with Electromagnetic Field System

  • 김정혁;박지봉;송풍근
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.311-311
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    • 2011
  • $TiN{\times}$박막은 우수한 내마모성 및 내부식성, 높은 경도 그리고 열적 안정성 등으로 인하여, 절삭공구 및 기계적 부품의 하드코팅, 2차 연료 전지용 확산방지막의 코팅재료로서 광범위하게 사용되어지고 있다. 일반적으로 $TiN{\times}$ 박막은 화학 기상 증착법(CVD)을 이용하였으나, 최근에는 대면적에 균일한 코팅이 가능하고 기판과 박막상의 부착력이 우수하며, 프로세스를 제어하기 쉬운 물리적 기상 증착법(PVD)의 스퍼터링법에 대한 관심이 고조되고 있다. 그러나 스퍼터링법으로 증착된 $TiN{\times}$ 박막의 물성은 주상구조와 국부적 표면결함을 포함하는 박막의 미세구조에 의존하기 때문에 주상구조 사이에 존재하는 Void 와 Pinhole 그리고 crack들이 원인으로 작용하여, 내부식성 및 기계적 특성이 급속도로 저하되는 단점이 있다. 이러한 단점을 보완하기 위해서, 본 연구에서는 기판온도를(RT, $200^{\circ}C$, $400^{\circ}C$)증가시켜 실험 하였다. 이는 온도증가에 따른 박막의 치밀화가 이루어지고 결함이 감소하여 내부식성 특성향상이 기대되어진다. 또한 플라즈마 밀도를 높이기 위해서, 기존 DC 마그네트론 스퍼터링법에 전자기장을 추가로 인가하였다. 이는 플라즈마 밀도증가에 따른 고반응성의 질소 래디컬의 생성율 증가에 기인하여 박막 형성시 질화반응을 촉진시킴으로써 박막의 치밀화 및 내부식성 특성향상이 기대되어진다.

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텅스텐 다공체의 기공특성에 미치는 분말특성 및 동결조건의 영향 (Effect of Powder Characteristic and Freeze Condition on the Pore Characteristics of Porous W)

  • 권나연;오승탁
    • 한국분말재료학회지
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    • 제19권4호
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    • pp.259-263
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    • 2012
  • Dependence of the freeze-drying process condition on microstructure of porous W and pore formation mechanism were studied. Camphene slurries with $WO_3$ contents of 10 vol% were prepared by milling at $50^{\circ}C$ with a small amount of dispersant. Freezing of a slurry was done in Teflon cylinder attached to a copper bottom plate cooled at $-25^{\circ}C$. Pores were generated subsequently by sublimation of the camphene during drying in air for 48 h. The green body was hydrogen-reduced at $800^{\circ}C$ for 30 min, and sintered in the furnace at $900^{\circ}C$ for 1 h. After heat treatment in hydrogen atmosphere, $WO_3$ powders were completely converted to metallic W without any reaction phases. The sintered samples showed large pores with the size of about $70{\mu}m$ which were aligned parallel to the camphene growth direction. Also, the internal wall of large pores and near bottom part of specimen had relatively small pores with dendritic structure due to the growth of camphene dendrite depending on the degree of nucleation and powder rearrangement in the slurry.

공압식 심실보조장치의 개발 및 평가 (Development and Evaluation of Pneumatic Ventricular Assist Device)

  • 이상훈;박이태;김삼현;한동선;이학중
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1995년도 춘계학술대회
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    • pp.247-250
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    • 1995
  • The purpose of this paper is to develop diaphragm-type pneumatic ventricular assist device(VAD) for clinical application and to evaluate its performance through the mock circulation system. The blood housing and diaphragm are made by coating pellethane on the metallic mold and the back plate is made by machining process. The relations of cardiac output(CO) vs. beat rate and CO vs. systolic-to-diastolic rate was estimated through the mock test and hemodynamic waves are recorded for the evaluation of VAD. As a result, the volume of blood pump is 70 ml, maximum CO is 5 L/min and CO has a close relation to the input resistance of blood pump. The hemodynamic data and waves showed this system can be applicable to the animal experiment.

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Fabrication of Ti/Ir-Ru electrode by spin coating method for electrochemical removal of copper

  • Kim, Joohyun;Bae, Sungjun
    • Environmental Engineering Research
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    • 제24권4호
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    • pp.646-653
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    • 2019
  • Recovery of valuable metals in the industrial wastewater and sludge has attracted an attention owing to limited metallic resources in the earth. In this study, we firstly fabricated Ti/Ir-Ru electrodes by spin coating technique for effective recovery of Cu in electrowinning process. Two different Ti/Ir-Ru electrodes were fabricated using 100 and 500 mM of precursors (i.e., Ir-Ru). SEM-EDX and AFM revealed that Ir and Ru were homogenously distributed on the surface of Ti plate by the spin coating, in particular the electrode prepared by 500 mM showed distinct boundary line between Ir-Ru layer and Ti substrate. XRD, XPS, and cyclic voltammetry also revealed that characteristics of IrO2, RuO2, and TiO2 and its electrocatalytic property increased as the concentration of coating precursor increased. Finally, we carried out Cu recovery experiments using two Ti/Ir-Ru as anodes in electrowinning process, showing that both anodes showed a complete removal of Cu (1 and 10 g/L) within 6 h reaction, but much higher kinetic rate constant was obtained by the anode prepared by 500 mM. The findings in this study can provide a fundamental knowledge for surface characteristics of Ti/Ir-Ru electrode prepared by spin coating method and its potential feasibility for effective electrowinning process.

전해도금에 의한 Ni-W 합금의 내식성 및 표면 전도도 특성 연구 (A Study on Corrosion Resistance and Electrical Surface Conductivity of an Electrodeposited Ni-W Thin Film)

  • 박제식;정구진;김영준;김기재;이철경
    • 한국표면공학회지
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    • 제44권2호
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    • pp.68-73
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    • 2011
  • A Ni-W thin-film was synthesized by electrodeposition, and its corrosion resistance and electrical surface conductivity were investigated. Amount of tungsten in the Ni-W thin-film increased linearly with current density during the electrodeposition, and crack-free and low-crystalline Ni-21 at.%W coating layer was obtained. Corrosion resistances of the Ni-W thin-films were examined with an anodic polarization method and a storage test in a strong sulfuric acid solution. As a result, the Ni-21 at.%W thin-film exhibited the greatest corrosion resistance, and maintained the electrical surface conductivity even after the severe corrosion test, which could be applicable as a surface treatment for advanced metallic bipolar plates in fuel cell or redox flow battery systems.

DC 스퍼터법과 비대칭 양극성 펄스 스퍼터법으로 제작된 고분자 전해질 연료전지 금속분리판용 CrN 코팅막의 특성 연구 (A Comparative Study of CrN Coatings Deposited by DC and Pulsed DC Asymmetric Bipolar Sputtering for a Polymer Electrolyte Membrane Fuel Cell (PEMFC) Metallic Bipolar Plate)

  • 박상원;전성용
    • 한국세라믹학회지
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    • 제50권6호
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    • pp.390-395
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    • 2013
  • Nanocrystalline CrN films were deposited on Si (100) substrates by means of asymmetric pulsed DC reactive magnetron sputtering. We investigated the growth behavior, corrosion resistance and mechanical properties of CrN films with a change in the duty cycle and pulse frequency. The grain size of the CrN films decreased from 25.4 nm to 11.2 nm upon a decrease in the duty cycle. The corrosion potentials for the CrN films by DC sputtering was approximately - 0.6 V, and it increased to - 0.3 V in the CrN films which underwent pulsed sputtering. The nanoindentation hardness of the CrN films also increased with a decrease in the duty cycle. This enhancement of the corrosion resistance and mechanical properties of pulsed sputtered CrN films could be attributed to the densification and surface smoothness of the microstructure of the films.

RF magnetron sputtering법으로 제조한 Al doped ZnO 박막의 산소함량과 압력변화에 따른 전기적 특성 변화 (Electrical properties of the Al doped ZnO thin films fabricated by RF magnetron sputtering system with working pressure and oxygen contents)

  • 김종욱;김홍배
    • 반도체디스플레이기술학회지
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    • 제9권4호
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    • pp.77-81
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    • 2010
  • The AZO thin films were deposited on the corning 1737 glass plate by the RF magnetron sputtering and effects of working pressure and oxygen contents on the electrical properties were investigated. XRD spectra showed a preferred orientation along the c-axis and a minimum FWHM for the 70mTorr. From the surface analysis (AFM), the number of crystal grain of AZO thin film increased as working pressure increased. The film deposited with 70mTorr of working pressure showed n-type semiconductor characteristic having suitable resistivity $-1.59{\times}10^{-2}{\Omega}cm$, carrier concentration $-10.1{\times}10^{19}cm^{-3}$, and mobility $-4.35cm^2V^{-1}s^{-1}$ while other films by 7 mTorr, 20 mTorr of working pressure closed to metallic films. The films including the oxygen represent stoichiometric composition similar to the oxide. The transmittance of the film was over 85% in the visible light range regardless of the changes in working pressure and oxygen contents.