• Title/Summary/Keyword: Coated layer

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낮은 수소 함유량을 갖는 유사 다이아몬드 박막의 몰리브덴 팁 전계 방출 소자 응용 (Application of Low-hydrogenated Diamond-like Carbon Film to Mo-tip Field Emitter Array)

  • 주병권;정재훈;김훈;이윤희;오명환
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제48권2호
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    • pp.76-79
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    • 1999
  • Low-hydrogenated DLC films were coated on the Mo-tip FEAs by 'layer-by-layer' process based on the plasma-enhanced CVD method. The hydrogen content in the DLC film deposited by the 'layer-by-layer' process was appeared to be remarkably lowered through SIMS analysis. Also, the low-hydrogenated DLC-coated Mo-tip FEA showed good potentiality for FED applications in terms of turn-on voltage, emission current, emission stability and light emitting uniformity.

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Three-Dimensional Nanofabrication with Nanotransfer Printing and Atomic Layer Deposition

  • 김수환;한규석;한기복;성명모
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.87-87
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    • 2010
  • We report a new patterning technique of inorganic materials by using thin-film transfer printing (TFTP) with atomic layer deposition. This method consists of the atomic layer deposition (ALD) of inorganic thin film and a nanotransfer printing (nTP) that is based on a water-mediated transfer process. In the TFTP method, the Al2O3 ALD growth occurs on FTS-coated PDMS stamp without specific chemical species, such as hydroxyl group. The CF3-terminated alkylsiloxane monolayer, which is coated on PDMS stamp, provides a weak adhesion between the deposited Al2O3 and stamp, and promotes the easy and complete release of Al2O3 film from the stamp. And also, the water layer serves as an adhesion layer to provide good conformal contact and form strong covalent bonding between the Al2O3 layer and Si substrate. Thus, the TFTP technique is potentially useful for making nanochannels of various inorganic materials.

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플라즈마 용사법에 의한 지르코니아 코팅에서의 잔류응력에 대한 연구 (Residual stresses on plasma sprayed zirconia coatings)

  • 류지호;강춘식
    • Journal of Welding and Joining
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    • 제7권4호
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    • pp.46-55
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    • 1989
  • Zirconia coatings are performed by the plasma spraying on the substrate of Al-Si alloy. In case of plasma sprayed ceramic coatings, it is important to control properly residual stress occurred during cooling process. Residual stress in coating layer varies with sprayed conditions and is influenced greatly by the coating layer thickness. Surface residual stress due to coating layer thickness is measured by X-ray diffraction method and the residual stress in coating layer is estimated by the deflection of coating layer when the restraint force in substrate was removed. When zirconia was coated on the substrate, tensile residual stress remains on zirconia coated surface layer. The tensile stress is increased to 0.35mm thickness and after 0.45mm thickness it is decreased abrouptly. A thick bond and composite coating reduce the zirconia surface stress and composite coating controls effectively the thick zirconia surface stress.

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국산 신문 용지에서 산화전분에 의한 표면 사이징 처리가 인쇄적성에 미치는 영향 (The Surface Sizing Effect of Oxidized Starch on the Printability of Newspaper)

  • 하영백
    • 한국인쇄학회지
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    • 제15권2호
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    • pp.25-40
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    • 1997
  • This research was carried out to investigated the effect of base paper and latex binder on printability and obtical properties of coated paper. Especially, it examined the effect of th pH of vase paper surface and functional groups of latices on the interactions between coating color components and on the structure of coated layer. It was found that the behavior of coating color containing amphoeric latex depends on the pH in the boundary region between coating color and base paper. Thus, the coating color formulated with amphoteric latex formed bulky coating layer by inducing stronger interaction between paper surface and coating components than the coating color with anionic latex. The coated paper with amphoteric latex showed better optical properties (i.e.gloss and optical) and printability (i.e. ink receptivity, wet ink receptivity, and ink set off) than the conventional anionic latex in the acidic and alkaline paper. However, dry pick strength of the coated paper was less decreased. This result indicated that amphoteric latex could also be applied practically to the alkaline paper.

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CAE 증착기술에 의해 TiN이 증착된 보론주철의 마모거동 (Wear Characterisitics of TiN-coated Boron Cast Iron by Arc Evaporation Process)

  • 송건;윤의성;안효석
    • Tribology and Lubricants
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    • 제8권1호
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    • pp.63-69
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    • 1992
  • In order to gain better understanding of wear behaviors of TiN-coated boron cast iron, tests and analyses were conducted with block-on disc type tribometer. TiN layer of thickness $2 \mu m$ and $4 \mu m$, coated by cathodic arc evaporation process, were experimentally investigated with the variation of applied load and sliding speed under dry sliding condition. Wear characteristics were expressed in terms of the three-dimentional wear map as well as the wear rate vs sliding speed and load. Comparisons of wear and friction characteristics between coated cast irons and uncoated cast irns were also made. Wear mechanism of TiN layer was explained in view of surface interaction between the mating surfaces. The thicker coating exhibited higher hardness and adhesion strength. the significance of stresses at the surface and in the subsurface was briefly discussed in relation to the wear behavior.

Mechanical Properties & Ablation Mechanism of SiC Coated Carbon/Carbon Composite by Pack-cementation Method

  • Kim, J.I.;Oh, I.S.;Joo, H.J.
    • Carbon letters
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    • 제2권1호
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    • pp.27-36
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    • 2001
  • The pack-cementation process is the method which is formed SiC coating layer to improve weak oxidation properties of CFRCs (carbon fiber-reinforced carbons). This method develops the anti-oxidation coating layer having no dimensional changes and good wetting properties. In this study to improve the oxidative resistance of the prepared 4D CFRCs, the surface of CFRCs is coated by SiC using pack cementation method. The mechanical properties of SiC-coated 4D CFRCs are measured by the 3-point bending test, and their ablation properties are investigated by the arc torch plasma test. From the results, it is found that both mechanical and ablation properties of SiC-coated 4D CFRCs are much better than bare CFRCs.

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TiN코팅 공정 개선에 의한 1Cr-1Mo-0.25V 강재의 피로강도 특성 (Fatigue Strength Characteristics of 1Cr-1Mo-0.25V Steel by Improved TiN Coated Processes)

  • 서창민;김경렬
    • 한국해양공학회지
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    • 제11권4호
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    • pp.49-60
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    • 1997
  • This paper deals with the effect of coating layer on the fatigue strength of TiN coated 1Cr-1Mo-0.25V steel prepared by using the arc ion plating (AIP) process, in which it was characterized by the presence of extractor grid (ion filter). The rotary bending fatigue tests were carried out under room air conditions, and the fatigue crack initiation and growth bwhavior were observed by using plastic replica method. As experimental results, it was found that the obvious improvement of fatigue life at lower stress region was confirmed in TiN coated specimen processed with ion filter. It was also exlained that the increase of fatigue life in the case of an improved AIP process with ion filter was attributed to the retardation of crack initiation of the substrate surface due to hard coating layer, more densly formed with the reduced size and density of droplets.

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용융염 침적법에 의한 VC Coating 금형강의 인성에 관한 연구 (A Study on the Toughness of Die Steel Coated with VC (vanadium carbide) by Immersing in Molten Borax Bath)

  • 이병권;남태운
    • 열처리공학회지
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    • 제6권2호
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    • pp.59-69
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    • 1993
  • Bending fracture strength test and impact strength test were made for VC coated die steels treated by immersing in molten borax bath and for hardened steels which were quenched and tempered, in order to clarify the effect of VC coating at $1000^{\circ}C$. The material used in this investigation was representative cold and hot work die steels STD11, STD61. The results obtained are as follows. 1) The bending fracture strength of VC coated die steel (STD11, STD61) was lessened with increasing the thickness of the VC coated layer. 2) With increasing the immersing time (imcreasing the thickness of the VC coated layer) the maximum hardness was obtained at 480 minutes holding, after that holding time hardness was decreased. 3) The impact strength of the VC coated die steel was not decreased. In the casse of STD11, it was higher than that of the quenched condition especially at low tempering temperature, and vice versa at high tempering temperature. However in the case of STD61 shows the result to the contrary.

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세라믹 코팅된 1Cr-1Mo-0.25V강의 피로균열성장 특성 (Fatigue crack growth properties of ceramic coated 1Cr-1Mo-0.25V steel)

  • 서창민;김경렬
    • 대한기계학회논문집A
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    • 제21권10호
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    • pp.1674-1682
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    • 1997
  • Fatigue tests were performed to investigate the effect of ceramic coatings as in TiN and TiCN on fatigue crack growth properties of ceramic coated 1Cr-1Mo-0.25V steel with different coating thickness in laboratory air conditions. The experimental results are described with respect to a Paris equation, da/dN=C(.DELTA.K)$^{m}$ , where the crack growth rate of coated specimens provided as similar growth rate as that of the uncoated specimen regardless of coating thickness. Furthermore, it was observed that the type of coating layer had virtually no effect on crack growth rate in the full region of stress intensity factor range. And it was also appeared that the final crack length of TiCN coated specimens was short compared to that of TiN coated, and the substrate specimens, in which it was inferred due to lowering the toughness of coated material from high hardness of TiCN coating layer itself.

전기선폭발법을 이용한 core/shell 구조 Ag/C 나노 입자의 제조 및 열처리조건에 따른 특성 (Synthesis of Core/shell Structured Ag/C Nano Particles and Properties on Annealing Conditions)

  • 전수형;엄영랑;이창규
    • 한국분말재료학회지
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    • 제17권4호
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    • pp.295-301
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    • 2010
  • Multi shell graphite coated Ag nano particles with core/shell structure were successfully synthesized by pulsed wire evaporation (PWE) method. Ar and $CH_4$ (10 vol.%) gases were mixed in chamber, which played a role of carrier gas and reaction gas, respectively. Graphite layers on the surface of silver nano particles were coated indiscretely. However, the graphite layers are detached, when the particles are heated up to $250^{\circ}C$ in the air atmosphere. In contrast, the graphite coated layer was stable under Ar and $N_2$ atmosphere, though the core/shell structured particles were heated up to $800^{\circ}C$. The presence of graphite coated layer prevent agglomeration of nanoparticles during heat treatment. The dispersion stability of the carbon coated Ag nanoparticles was higher than those of pure Ag nanoparticles.