• 제목/요약/키워드: Nano-diamond

검색결과 172건 처리시간 0.03초

SPM을 이용한 접촉조건 변화에 따른 미소응착 특성 연구 (Effect of Contact Conditions on the Micro-adhesion Characteristics using SPM)

  • 윤의성;박지현;양승호;공호성
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
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    • pp.18-22
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    • 2000
  • An experimental study was carried out to investigate the effect of nano-contact condition on the nano-adhesion phenomena. SPM(scanning probe microscope) tips with different radius of curvature were fabricated by a series of masking and etching processes. DLC(diamond-like carbon) and W-DLC (tungsten-incorporated diamond-like carbon) were coated on (100) silicon wafer by PACVD(plasma assisted chemical vapor deposition). Pull-off forces of Pure Si-wafer, DLC and W-DLC were measured with SPM(scanning probe microscope). Also, the same series of tests were carried out with the tips with different radius of curvature. Results showed that DLC and W-DLC showed much lower pull-off force than Si-wafer and Pull-off force increased with the tip radius.

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평삭공정에서 경면가공을 위한 단결정 및 다결정 다이아몬드 다중공구의 가공성 평가 (Comparison of Machinability Between PCD Tool and SCD Tool for Large Area Mirror Surface Machining Using Multi-tool by Planer)

  • 김창의;최환진;전은채;제태진;강명창
    • 한국분말재료학회지
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    • 제20권4호
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    • pp.297-301
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    • 2013
  • Mirror surface machining for large area flattening in the display field has a problem such as a tool wear and a increase in machining time due to large area machining. It should be studied to decrease machining time and tool wear. In this paper, multi-tool machining method using a PCD tool and a SCD tool was applied in order to decrease machining time and tool wear. Machining characteristics (cutting force, machined surface and surface roughness) of PCD tool and SCD tool were evaluated in order to apply PCD tool to flattening machining. Based on basic experiments, the PCD/SCD multi-tool method and the SCD single-tool method were compared through surface roughness and machining time for appllying large area mold machining.

Photocatalytic activity of $TiO_2$ on nano-diamond powder prepared by Atomic Layer Deposition

  • Kim, Kwang-Dae;Dey, Nilay Kumar;Seo, Hyun-Ook;Kim, Dong-Wun;Nam, Jong-Won;Sim, Chae-Won;Jeong, Myung-Geun;Kim, Young-Dok
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.425-425
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    • 2011
  • The photocatalytic decomposition of toluene gas was investigated with $TiO_2$ on nano-diamond powder (NDP) under UV irradiation. Atomic layer deposition (ALD) was used for the growth of $TiO_2$ on the NDP. The structure and surface properties of catalysts were characterized by X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM). The photocatalytic activity for the toluene decomposition was evaluated by measuring the concentration change of toluene and $CO_2$ gas with gas chromatography (GC)-flame ionization detector (FID) system. The photocatalytic activities of $TiO_2$/NDP catalysts were compared with that of P-25. The rate of initial photocatalytic decomposition of toluene for the $TiO_2$/NDP catalysts was relatively lower when compared to P-25. The photocatalytic activity of P-25 was rapidly decreased with time, whereas, the deactivation of $TiO_2$/NDP catalysts was less pronounced. Therefore, as the reaction time increased, the photocatalytic activity of $TiO_2$/NDP catalysts became higher than that of P-25. The intermediates such as benzaldehyde or benzoic acid, etc were more easily adhered to the active site on the P-25 surface during reaction, resulting in easier deactivation of P-25. These results could be confirmed using FT-IR spectroscopy. We suggest that the NDP used as substrate can reduce the deactivation of $TiO_2$ on the surface.

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나노결정질 다이아몬드 seeding 효율 향상을 위한 silicon 표면 texturing (Silicon surface texturing for enhanced nanocrystalline diamond seeding efficiency)

  • 박종천;정옥근;김상윤;박세진;윤영훈;조현
    • 한국결정성장학회지
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    • 제23권2호
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    • pp.86-92
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    • 2013
  • 나노결정질 다이아몬드 박막 증착을 위한 전처리 공정으로 $SF_6/O_2$ 유도결합 플라즈마를 이용하여 Si 기판 표면을 texturing하였다. $SF_6/O_2$ 플라즈마 texturing은 2~16 범위의 매우 넓은 정규화된 표면 조도 선택성을 제공할 수 있음을 확인하였다. Texturing된 Si 기판 표면의 나노 다이아몬드 입자 seeding 이후 기존 기계적 연마 전처리에 비해 현저히 향상된 ${\sim}6.5{\times}10^{10}cm^{-2}$의 높은 핵형성 밀도를 확보하였다.

자기 조립 분자막의 표면파손특성 및 미세 금속 구조물 제작에의 응용 (Surface Damage Characteristics of Self-Assembled Monolayer and Its Application in Metal Nano-Structure Fabrication)

  • 성인하;김대은
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2002년도 제35회 춘계학술대회
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    • pp.40-44
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    • 2002
  • The motivation of this work is to use SAM(Self-Assembled Monolayer) for developing a rapid and flexible non-photolithographic nano-structure fabrication technique which can be utilized in micro-machining of metals as well as silicon-based materials. The fabrication technique implemented in this work consists of a two-step process, namely, mechanical scribing followed by chemical etching. From the experimental results, it was found that thiol on copper surface could be removed even under a few nN normal load. The nano-tribological characteristics of thiol-SAM on various metals were largely dependent on the native oxide layer of metals. Based on these findings, nano-patterns with sub-micrometer width and depth on metal surfaces such as Cu, Au and Ag could be obtained using a diamond-coated tip.

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나노스케일 표면돌기 간의 미세접촉에 대한 해석 (Analysis of Nano-contact Between Nano-asperities Using Atomic Force Microscopy)

  • 안효석;장동영
    • 한국생산제조학회지
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    • 제18권4호
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    • pp.369-374
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    • 2009
  • In micro/nano-scale contacts in MEMS and NEMS, capillary and van der Waals forces generated around contacting micro-asperities significantly influence the performance of concerning device as they are closely related to adhesion and stiction of interacting surfaces. In this regard, it is of prime importance to accurately estimate the magnitude of surface forces so that an optimal solution for reducing friction and adhesion of micro/nano-surfaces may be obtained We introduced an effective method to calculate these surface forces based on topography information obtained from an atomic force microscope. This method was used to calculate surface forces generated in the contact interface formed between diamond-like carbon coating and $Si_3N_4$ ball. This method is shown to effectively demonstrate the influence of capillary force in the contact area, especially in humid atmosphere.

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