• 제목/요약/키워드: Ceramic slurry

검색결과 251건 처리시간 0.025초

PDP 투명 유전체용 Bi계 프릿트 필름의 제조 및 특성분석 (Fabrication and Characterization of Bi-Based Frit Film for PDP Transparent Dielectric Front Panel)

  • 이상진;김주원;황종희
    • 한국세라믹학회지
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    • 제44권10호
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    • pp.548-553
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    • 2007
  • Ceramic green sheets consisting Bi-based glass frit were fabricated for an application to PDP transparent dielectric front panel. The dispersion condition of the slurry for tape casting was pre-examined, and two kinds of hinder and plasticizer were used in the non-aqueous slurry system. In the fabrication process for the frit film, the properties such as dry and firing shrinkage, elongation, and transmittance were examined at the condition of various mixing ratio of plasticizers. In the mixing ratio of polyethylene glycol to dibutyl phthalate of 3:5wt%, a good adhesion, elongation and transmittance were observed at the firing temperature of $580^{\circ}C$. The photograph for the cross section of the interface was also showed a dense microstructure.

Preparation of Granule Powders for Thermal Spray Coating by Utilization of Pyrophyllite Minerals

  • Kim, Yong-Hyeon;Shin, Pyung-Woo;Lee, Sang-Jin
    • 한국세라믹학회지
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    • 제53권5호
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    • pp.557-562
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    • 2016
  • Pyrophyllite granule powders for thermal spray coating were successfully prepared through spray drying process. To produce a stable slurry, commercial pyrophyllite powder of $45{\mu}m$ in size was ball-milled for reduction of the size to $2{\sim}3{\mu}m$ and a dispersant was added to control the viscosity. Dense and spherical granules (average granule size : $59{\mu}m$) were prepared under conditions of 12,500 rpm for rotation velocity of the atomizer and 100 cps for slurry viscosity. The granules were then heat treated at $1,200^{\circ}C$ for proper handling strength and flow properties. The final granules had an apparent density of $0.725g/cm^3$ and a flow rate of 2.5 g/sec, which represent excellent properties to be used as the granule powder for thermal spray coatings.

슬러리 분무열분해에 의한 초미립 티탄산 바륨 분말 제조 (Preparation of Ultrafine Barium Titanate Powder by Slurry Spray Pyrolysis)

  • 이종호;허강헌;이정수
    • 한국세라믹학회지
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    • 제46권2호
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    • pp.137-145
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    • 2009
  • A remarkable improvement of the productivity in barium titanate by slurry spray pyrolysis process was realized by supplying solid source slurry into the rector. The produced barium titanate powders showed uniform powder properties, and reproducibility with higher tetragonality in the range of 80$\sim$200 nm, case by case. The secondary calcination experiments of the as-prepared powders by spray pyrolysis revealed that the powders as-prepared over 700$^{\circ}C$ showed perfectly different behavior with the lower temperature's ones and the solid state reaction’s case. The result was discussed in terms of the reaction mechanism based on the activation energy analysis.

슬러리 가압함침에 의한 3D Mullite 섬유 Preform의 알루미나 입자 충전 (Packing of Alumina Particles in 3D Preform of Mullite Fiber by Slurry Pressure-Infiltration)

  • 심수만
    • 한국세라믹학회지
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    • 제50권6호
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    • pp.528-532
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    • 2013
  • Well-dispersed slurries of submicron-sized alumina powders were pressure-infiltrated in 3D preforms of mullite fibers and the effects of the particle size and infiltration pressure on the particle packing characteristics were investigated. Infiltration without pressure showed that the packing density increased as the particle size decreased due to the reduction of the friction between the particles and the fibers. The infiltrated preforms contained large pores in the large voids between the fiber tows and small pores in the narrow voids between the individual fibers. Pressure infiltration resulted in a packing density of 77% regardless of the particle size or the infiltration pressure(210 ~ 620 kPa). Pressure infiltration shortened the infiltration time and eliminated the large pores in preforms infiltrated with the slurries of smaller particles. The slurry pressure-infiltration process is thus an efficient method for the packing of matrix materials in various preforms.

Properties of Polysiloxane Coated Borosilicate Lining Blocks

  • Song, Jeongho;Song, Ohsung
    • 한국세라믹학회지
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    • 제54권6호
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    • pp.525-529
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    • 2017
  • To improve the thermal resistance of a porous borosilicate lining block, we prepared and applied polysiloxane-fumed silica-ethanol slurry on top of the block and fired the coating layer using a torch for 5 minutes at $800^{\circ}C$. We conducted magnified characterizations using a microscope and XRD analysis to observe phase transformations, and TGA-DTA analysis to determine the thermal resistance. Thermal characterizations showed improved heat resistance with relatively high polysiloxane content slurry. Cross-sectional optical microscope observation showed less melting near the surface and decreased pore formation area with higher polysiloxane content slurry. XRD analysis revealed that the block and coating layer were amorphous phases. TGA-DTA analysis showed an endothermic reaction at around $550^{\circ}C$ as the polysiloxane in the coating layer reacted to form SiOC. Therefore, coating polysiloxane on a borosilicate block contributes to preventing the melting of the block at temperatures above $800^{\circ}C$.

집진장치의 유입구조에 따른 세라믹필터의 철입자 제거특성에 미치는 영향 (Effect of inlet structure of filtration system on the removal characteristics of iron particles by ceramic candle filters)

  • 박영옥;정주영;서용칠
    • 한국입자에어로졸학회지
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    • 제5권4호
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    • pp.189-197
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    • 2009
  • Wet-type particulate removal system is employed in most of ironmaking processes. These de-dusting systems require additional downstream aggregates for treatment of water and for drying of the collected slurry. Thus dried slurry can be pressed in shape of briquettes and recycled in the steelmaking process. Different from the wet-type, the dry-type particulate removal systems generate no slurry. A high-temperature, high-pressure de-dusting system with inertial inlet was developed. The target application of this system was to remove particulate matter generated from the novel ironmaking process and other steelmaking processes. In this study we conducted tests with this newly developed system to evaluate the performance of the silica-carbide (SiC) ceramic filters. In addition, for purpose of comparison, we also conducted tests with a unit which has conventional direct inlet. Fe-Particles collected from the novel ironmaking process were used in our tests as test dusts. The temperature and the pressure were kept constant at their respective values $800^{\circ}C$ and $3kg_f/cm^2$.

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Indium Tin Oxide (ITO) Coatings Fabricated using Nanoparticle Slurry and Sol

  • Cheong, Deock-Soo;Yun, Dong-Hun;Kim, Dong-Hwan;Han, Kyoung-R.
    • 한국세라믹학회지
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    • 제48권6호
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    • pp.516-519
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    • 2011
  • Indium tin oxide (ITO) coatings were made using an ITO slurry and an ITO sol. This was achieved by dispersing nanosized ITO powder in a mixed solvent without any dispersant and developing an adhesive ITO sol from indium acetate and tin tetrachloride in a mixture of DMF and n-butanol. Coating was carried out in one step by spin coating an ITO slurry, which was then followed by an ITO sol over it. Here, the sol penetrates into the nano ITO particle layers to make them adhere to each other as well as to a glass substrate. This is then followed by sintering at 500$^{\circ}C$ for 1 h to produce a uniform film consisting of ITO particles of about 50 nm and 10 nm. ITO films were obtained with sheet resistances from 450 to 1500 ohm/${\Box}$ by varying spin speed and concentration. Transmittance is higher than 90% at 550 nm.