• 제목/요약/키워드: copper particles

검색결과 261건 처리시간 0.024초

수열흡착법을 이용한 은 점코팅된 구리 나노분말의 합성과 미세조직 (Microstructure and Synthesis of Ag Spot-coated Cu Nanopowders by Hydrothermal-attachment Method using Ag Colloid)

  • 김형철;한재길
    • 한국분말재료학회지
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    • 제18권6호
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    • pp.546-551
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    • 2011
  • Ag spot-coated Cu nanopowders were synthesized by a hydrothermal-attachment method (HA) using oleic acid capped Ag hydrosol. Cu nano powders were synthesized by pulsed wire exploding method using 0.4 mm in diameter of Cu wire (purity 99.9%). Synthesized Cu nano powders are seen with comparatively spherical shape having range in 50 nm to 150 nm in diameter. The oleic acid capped Ag hydrosol was synthesized by the precipitation-redispersion method. Oleic acid capped Ag nano particles showed the narrow size distribution and their particle size were less than 20 nm in diameter. In the case of nano Ag-spot coated Cu powders, nanosized Ag particles were adhered in the copper surface by HAA method. The components of C, O and Ag were distributed on the surface of copper powder.

SHS공정에 의한 TiC-Ni-Mo 분말 합성 및 소결체 제조 (A Study on Self-Propagating High-Temperature Synthesis of TiC-Ni-Mo Based Cermet)

  • 송인혁;전재호;한유동
    • 한국세라믹학회지
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    • 제35권7호
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    • pp.749-756
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    • 1998
  • TiC-Ni and TiC-Ni-Mo cermet powders were produced by Self-propagating High temperature Synthesis (SHS) process. The cooling rate of synthesized powders were controlled by using the V-shaped copper jig and the carbide size decreased with increasing the cooling rate I. e decreasing the width of copper jig Round shape carbide particles were produced after SHS reaction in TiC-Ni as well as TiC-Ni-Mo powders. Local segregation of Mo rich phases was observed in SHS powder of TiC-Ni-Mo and the uneven dis-triobution of Mo promoted the faster growth rate of carbide particles during sintering compared to the same composition specimen with commercial TiC powder. Howogeneous microstructure of TiC-Ni-Mo cermet was obtained when the elemental Mo powder was mixed with the SHS powder of TiC-Ni.

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Reduction Behaviors of Nitric Oxides on Copper-decorated Mesoporous Molecular Sieves

  • Cho, Ki-Sook;Kim, Byung-Joo;Kim, Seok;Kim, Sung-Hyun;Park, Soo-Jin
    • Bulletin of the Korean Chemical Society
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    • 제31권1호
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    • pp.100-103
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    • 2010
  • In this study, NO reduction behaviors of copper-loaded mesoporous molecular sieves (Cu/MCM-41) have been investigated. The Cu loading on MCM-41 surfaces was accomplished by a chemical reduction method with different Cu contents (5, 10, 20, and 40%). $N_2/77$ K adsorption isotherm characteristics, including the specific surface area and pore volume, were studied by BET's equation. NO reduction behaviors were confirmed by a gas chromatography. From the experimental results, the Cu loading amount on MCM-41 led to the increase of NO reduction efficiency in spite of decreasing the specific surface area of catalysts. This result indicates that highly ordered porous structure in the MCM-41 and the presence of active metal particles lead the synergistical NO reduction reactions due to the increase in adsorption energy of MCM-41 surfaces by the Cu particles.

구리입자/메타아라미드 수지 복합재료 도포 스테인리스 철판의 적외선 방사 특성 (Infrared Emissivity of Stainless Steel Coated with Composites of Copper Particle and m-Aramid Resin)

  • 오초롱;김선미;박규상;최성만;이대수;명노신;김원철
    • 한국추진공학회지
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    • 제21권1호
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    • pp.1-7
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    • 2017
  • 항공기 엔진 배기노즐 표면으로부터 적외선 방사를 낮추기 위한 연구의 일환으로 스테인리스 스틸 표면을 구리입자/메타 아라미드 수지 복합재료로 도포하여 $320^{\circ}C$에서 적외선 방사율을 측정하였다. 일반적인 충전제 입자 바인더 합성수지의 경우 $300^{\circ}C$이전에서 대부분 열분해를 일으키지만 메타 아라미드 수지는 $320^{\circ}C$에서도 열안정성을 보여 구리입자 분산 내열성 매트릭스 수지로 적합한 것으로 나타났다. 본 연구에서는 첨가한 구리입자 함량은 부피기준으로 0 ~ 70% 까지 변화시켰다. 구리입자/메타아라미드 복합재료 수지로 도포된 시편은 $320^{\circ}C$에서 적외선 방사율 측정 실험 후에 접착력이 우수하였다. 그리고 구리입자 함량이 부피 기준으로 50%인 구리입자/메타 아라미드 수지를 도포함으로써 시편의 $320^{\circ}C$ 적외선 방사율을 0.6 까지 낮출 수 있었다.

Velocity and temperature profiles of Al/water micro fluid in a circular tube with swirl

  • Chang, Tae-Hyun;Lee, Kwon Soo;Lee, Chang-Hoan
    • Journal of Advanced Marine Engineering and Technology
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    • 제37권7호
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    • pp.677-684
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    • 2013
  • A lot study of convection heat transfer on internal flow has been extensively conducted in the past decades using of high specific surface area, increasing heat transfer coefficient, swirling flow and improving the transport properties. This study concerned with the application of a tangential slot swirl generator for improving heat transfer in a horizontal circular copper tube. The Al particles(about $100{\sim}130{\mu}m$) was employed for this experimental work. 3D PIV(particle image velocimetry) technique has employed to measure velocity profiles of Al particles with and without swirl flow. The copper tube is heated uniformly by winding of a heating coil for heat transfer work, having a resistance of 9 ohm per meter. Experiments are performed in the Reynolds number range of 6,800~12,100 with swirl and without swirl using Al particles. Experimental data for comparison of Nusselt number is presented that of with swirl and without swirl along the test tube for the Reynolds numbers. The Nusselt number is improved with increasing of Reynolds numbers or swirl intensities along the test tube. The Nusselt number with swirl flow is about 60.0% to 119.0% higher than that obtained by the Dittus-Boelter equation.

고속 구리제트에 대한 알루미나-탄화규소 복합재료의 충돌 저항물성 (Impact Resistance of Al2O3-SiC Composites Against High Velocity Copper Jet)

  • 김창욱;이형복
    • 한국세라믹학회지
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    • 제43권10호
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    • pp.660-665
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    • 2006
  • The mechanical properties of $Al_2O_3$-SiC composites manufactured with adding various amount and size of SiC particles have been measured and analyzed. Generally, the elastic modulus of the composites shows about 50% less than that of PL-8 (45 wt% $Al_2O_3$-51 wt% $SiO_2$-4 wt% other oxides), but the flexural strength is similar with each other. The impact resistance property of $Al_2O_3$-SiC composite against high velocity copper jet was lower than that of PL-8 when SiC particles of approximately 3 $\mu$m diameter was added to. It is caused probably due to the micro-pores made by oxidation of SiC particles. However, in the case of the less-weighted $Al_2O_3$-SiC composite adding to 10 wt% SiC with average diameter of 10 $\mu$m and sintering at 1200$^{\circ}C$, the impact resistance property was improved up to 37 percent compared with that of PL-8.

입자 사이즈에 따른 Cu 필름의 에어로졸 성막 거동에 대한 연구 (Study on Aerosol Deposition Behavior of Cu Films According to Particle Size)

  • 이동원;오종민
    • 한국전기전자재료학회논문지
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    • 제30권4호
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    • pp.235-240
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    • 2017
  • The effect of particle sizes on the aerosol deposition (AD) of Cu films is investigated in order to understand the deposition behaviors of metal powder during the AD process. The Cu coatings fabricated by using $2{\mu}m$ Cu powders had a dense microstructure, a high deposition rate ($1.6{\pm}0.2{\mu}m/min$), and low resistance ($9.42{\pm}0.4{\mu}{\Omega}{\cdot}cm$) compared to that from using Cu powder with a particle size greater than $5{\mu}m$. Also, from estimating the internal micro-strain of Cu films, the Cu coatings fabricated by using $2{\mu}m$ Cu particles exhibited a high micro-strain value of $3.307{\times}10^{-3}$. On the other hand, the strain of Cu coatings fabricated with $5{\mu}m$ particles was decreased to $2.76{\times}10^{-3}$. These results seem to show that the impacted Cu particles are compressed and flattened by shock waves, and that their bonding is associated with the high internal micro-strain caused by plastic deformation.

WCu-Cu 전기접점의 마찰용접 특성 연구 (A Study on Friction weldability of Copper-Tungsten Sinterd Alloy to Copper)

  • 안용호;윤기갑;민택기;한병성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 D
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    • pp.1934-1937
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    • 1999
  • A copper-tungsten sintered alloy(Cu-W) has been friction-welded to a tough pitch copper (Cu) in order to investigate friction weldability. The tensile strength of the friction welded joint was increased up to 87% of the Cu base metal under the condition of friction time 1.0 see, friction pressure 40MPa and upset pressure 100MPa, upset time 5.0 sec. And it is related to upset pressure rather than friction time. Mixed layer was formed in the Cu adjacent weld interface and W particles which were included in mixed layer could induce fracture in the Cu adjacent to the weld interface. Thickness of mixed layer was reduced as upset pressure increase.

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