• Title/Summary/Keyword: powder preparation

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Preparation of Porous Glass by the Sintering (소결법에 의한 다공질유리의 제조)

  • 박용완;이준영
    • Journal of the Korean Ceramic Society
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    • v.31 no.9
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    • pp.957-968
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    • 1994
  • Manufacturing process of porous glass by the filler method was studied. Commercial soda-lime-silicate glass powder was mixed with inorganic salt as the filler such as KCl, K2SO4, Na2SO4. Sintering shrinkages of mixed powders with the variation of sintering temperature were compared, and the effects of the fillers to shrinkages of mixed powder were increased in the order of Na2SO4${\mu}{\textrm}{m}$ of pore diameter were manufactured when the filler sizes 100~200 ${\mu}{\textrm}{m}$. The open pore volume of porous glass is determined by the quantity of filler and porous glasses having open pore volume between 30 and 70 vol% are available. Available sintering temperature range for preparation of porous glass is from the softening temperature of the glass powder to eutectic melting temperature of DTA curve of mixed powder.

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Preparation of Energetic Metal Particles and Their Stabilization (에너제틱 금속입자 제조 및 안정화 기술)

  • Lee, Hye Moon;Kim, Kyung Tae;Yang, Sangsun;Yu, Ji-Hun;Kim, Yong-Jin
    • Particle and aerosol research
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    • v.9 no.3
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    • pp.173-185
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    • 2013
  • Oxidations of metal generate large quantity of thermal and light energies but no toxic pollutants, so that metals with high calorific values, such as beryllium, boron, aluminum, magnesium, and lithium, are possible to be used as clean fuels instead of fossil fuels. However, they are so explosive due to very high oxidation rates that they should be stabilized by their surface passivation with oxides, organics and inorganics. For reasonable use of energetic metal particles as solid fuel, therefore, some detail information, such as thermal properties, preparation and passivation methods, and application area, of the energetic metals is introduced in this manuscript.

Preparation Method of Spherical 0.9PMN-0.1PT Powder (구형의 PMN-PT 분말 제조 방법)

  • 임경란;정순용;김창삼
    • Journal of the Korean Ceramic Society
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    • v.39 no.7
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    • pp.687-692
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    • 2002
  • Preparation of spherical single-perovskite phase PMN-PT powder was tried by surface modification of the precursor powder with magnesia sol. The ball-milled mixed powder was heat treated at 550$\^{C}$/l h to remove any volatiles. The calcined powder was treated with the magnesia sol of 0.3-1.0 wt% and followed by calcination at 800$\^{C}$/l h to give rise to single phase perovskite PMN-PT powders. The powder with a binary size of <0.3 ㎛ and -2 ㎛ was obtained for MgO(0.3), but the spherical, agglomerate-free powder of 0.5-0.8 ㎛ was obtained for MgO(0.6) as well as for MgO(1.0).

TEM Specimen Preparation Method of Gibbsite Powder for Quantitative Structure Analysis (정량 구조 분석을 위한 Gibbsite 분말의 TEM 시편 준비법)

  • Kim, Young-Min;Jeung, Jong-Man;Lee, Su-Jeong;Kim, Youn-Joong
    • Applied Microscopy
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    • v.32 no.4
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    • pp.311-317
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    • 2002
  • There is great requirement on the TEM specimen preparation method with particle size selectivity as a prerequisite for the quantitative structure analysis on the materials such as gibbsite powder, which generally forms a large agglomerate and shows a variation of transition process depending on their sizes. In this experiment, we made an attempt to give a methodology for the TEM specimen preparation of powder with the size selectivity. After mixing 1 wt% gibbsite powder with ethanol solvent, gibbsite suspension was prepared by application of ball-milling and ultrasonification with addition of 0.25 vol% dispersion agent, Darvan C, which was diluted into distilled water by the ratio 1:19. Appling the static sedimentation method to gibbsite suspension after estimation of the sedimentation time by the measurement of accumulative concentration variation, we acquired TEM specimens with well-dispersed and size selected gibbsite particles in nm scale. Overall picture of each sample was taken by SEM and morphology of each dispersed particle was imaged by TEM. Raw and processed gibbsite powders were also examined by XRD to investigate whether they were suffered from phase change during the process or not.