• 제목/요약/키워드: powder of fine

검색결과 1,185건 처리시간 0.03초

화학 증착법에 의한 $TiO_2$ 초미분의 제조 및 입자 특성에 관한 연구 (Synthesis and Characterization of $TiO_2$ Ultrafine Powder by Chemical Vapor Deposition)

  • 염선민;이성호;김광호
    • 한국세라믹학회지
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    • 제32권1호
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    • pp.37-44
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    • 1995
  • TiO2 fine powders were synthesized using oxygenolysis and hydrolysis reaction of TiCl4 vapor in gas phase. The TiO2 powder synthesized showed morphological differences depending on reaction system as follows: TiCl4-O2 reaction system produced the monosized particles having polyhedral shape with well-defined crystal planes and the particles did not agglomerate into secondary particles. TiCl4-H2O reaction system, whereas, produced the spherical secondary particles which consisted of fine primary particles. Other powder characteristics such as particle size, impurity content and rutile content are also reported in this study.

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공침법을 이용한 Ag-Ni 초미분 제조 (Production of Ag- Ni fine powder by coprecipitation)

  • 김봉서;우병철;변우봉;이희우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 C
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    • pp.1342-1344
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    • 1994
  • Silver-Nickel alloy has been used as a electrical contact material for low voltage, low current. Since the solubility between Ag and Ni is very low, it is difficult to produce Ag-Ni alloy by using conventional melting method and disperse Ni powder homogeneously in Ag matrix. In this study we have been produced fine Ag-Ni alloy powder by using coprecipitation method. Firstly, we have produced silver-nickel nitrate solution by dissolving the Ag and Ni ingot in nitric acid solution and then, coprecipitate (Ag, Ni)carbonate dropping Ag-Ni nitrate solution to sodium carbonate solution. (Ag, Ni) carbonate is heat-treated in $H_2$ atmosphere, $400^{\circ}C$ and it has been analysed by TGA, SEM, XRD, ICP. It is represented Silver-Nickel alloy powder in the particle range of $0.1{\sim}0.5{\mu}m$.

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금속 Alkoxide를 이용한 LAS계 내열세라믹스의 제조에 관한 연구(I) (Preparation of the LAS Ceramics for Heat Resistance using Metal Alkoxide (I))

  • 김형태;이응상
    • 한국세라믹학회지
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    • 제30권12호
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    • pp.987-992
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    • 1993
  • In order to synthesize the heat resistance ceramics of LAS system, we studied on preparing the fine powder with homogeneity by sol-gel method using metal alkoxide. Various results were obtained depending on the composition and process. When the amount of H2O added at initial stage is higher than 10mol/$\ell$, and when the amount of catalyst is 0.1mol/$\ell$, the particle size of synthesized hydrate becomes finer. On condition that partial prehydrolysis time of TEOS is more than 50 hours, the monosized fine powder is obtained(below 1${\mu}{\textrm}{m}$).

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수열반응으로 합성한 Hydroxyapatite 초미분말의 소결특성 (Sintering Behavior of Ultra-fine Hydroxyapatite Powders Synthesized by Hydrothermal Reaction)

  • 최재웅;조성원;최상홀
    • 한국세라믹학회지
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    • 제31권11호
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    • pp.1265-1270
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    • 1994
  • Ultra-fine hydroxyapatite powder were synthesized by the hydrothermal reaction at 10 atm, 3 hrs of Ca(OH)2 suspension with (NH4)2HPO4 solution, and were characterized sintering behavior. Sintered bodies of hydroxyapatite powders which synthesized by hydrothermal reaction method has less weight loss, less sintering shrinkage and superior mechanical property, and was more dense than sintered bodies of hydroxyapatite powder which synthesized by wet method. Sintered bodies were hydroxyapatite single phase. When soack in Ringer's solution for 2 weeks, hydroxyapatite powders preserved hydroxyapatite and sintered body absorbed trace of Ca2+ ion with soaked time.

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순환잔골재 품질개선을 위한 건식생산기술의 개발 및 검증에 관한 연구 (Study on the Development and Verification of Dry Manufacturing Technology for improving Quality of Recycled Fine Aggregate)

  • 나철성;최형길;김영덕;권수길;김규용;김무한
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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    • pp.469-472
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    • 2008
  • 본 연구에서는 경제성, 환경부하저감성 및 순환잔골재의 품질개선효과가 우수한 순환잔골재 건식생산기술로서 고속회전충격식 비중분리장치 및 원심력 미분말 집진장치 등으로 구성된 건식생산시스템을 개발하고 순환잔골재의 품질을 평가하여 성능을 검증하고자 한다. 그 결과 고속회전충격에 의한 순환잔골재의 파쇄작용, 원심력 및 질량차에 의한 미분말과 미세분진의 분리 및 집진작용, 질량차에 의한 미세립분의 분리 회수에 의해 표준입도, 절건밀도 등 순환잔골재의 품질개선에 효과가 있는 것으로 확인되었다.

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