• Title/Summary/Keyword: tape casting method

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Characteristics and Microstructure of Matrix Retaining Electrolyte in Phosphoric Acid Fuel Cell Prepared by Tape Casting (Tape Casting법으로 제조한 인산형 연료전지 전해질 매트릭스의 미세구조 및 특성)

  • 윤기현;허재호;장재혁;김창수
    • Journal of the Korean Ceramic Society
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    • v.31 no.4
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    • pp.375-380
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    • 1994
  • Matrices retaining electrolyte in phosphoric acid fuel cell were prepared with SiC to SiC whisker mixing ratios of 1:0.5, 1:1, 1:1.5, 1:2, 1:3 by tape casting method. When viscosity of the slurry was 5.9 poise and the SiC to SiC whisker mixing ratios were 1:1, 1:1.5, 1:2, the ranges of porosity, acid absorbency and bubble pressure were 80~90%, 2.5~6 and 700~2200 mmH2O, respectively. Those ranges are acceptable for a practical electrolyte-retaining matrix. With increasing the mixing ratio of SiC whisker to SiC, the porosity and the vol.% of large pores in the main pore size distribution which is between 1 and 10 ${\mu}{\textrm}{m}$, increased rapidly. Impedance spectroscopy was measured to know characteristics of matrix inside and contact region of matrix to catalyst layer. When the SiC to SiC whisker mixing ratio was 1:2, hydrogen ions were transported in the matrix most effectively because of high ionic conductivity and low activation energy due to high acid absorbency in spite of high interfacial resistance. The cell current density of the cell made using the matrix was 220 mA/$\textrm{cm}^2$ at 0.7 V.

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The Characterizations of Tape Casting for Low Temperature Sintered Microwave Ceramics Composite (저온소성 마이크로파 유전체 세라믹스 복합체의 Tape Casting특성)

  • Lee, Woo-Suk;Kim, Chang-Hwan;Ha, Mun-Su;Jeong, Soon-Jong;Song, Jae-Sung;Ryu, Bong-Ki
    • Journal of the Korean Ceramic Society
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    • v.42 no.2 s.273
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    • pp.132-139
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    • 2005
  • Sintering behavior of $BaO-Nd_{2}O_3-TiO_2$ with a Pb-based glassceramics frit were investigated in order to understand an effect of glassceramics as a low temperature sintering agent on dielectric ceramics. A green sheet form was fabricated through tape casting method with the glassceramic fut added $BaO-Nd_{2}O_3-TiO_2$. The dispersion properties, rheological properties and final density of dielectric composit slurry as a function of amount and composition of organic additives was examined. The dispersants' addition was effective in controlling dispersion of the ceramics in solution. The addition of excessive dispersant showed adverse effect on dispersion. The prepared slurries, containing ceramic : powders, glass-ceramics and various kinds of organic viechles, exhibited typical shear thinning behavior. The best properties of tape casting appeared powder to solvent ratio 65 : 35 and amount of the binder 6 wt$\%$ and plasticizer 3 wt$\%$. The viscosity of the slurry was 677 cps and green/sintered density in the tape was $3.3 g/cm^3,\;5.56 g/cm^3$ respectively.

Rheology of Slurries and Effects of Polymer Volume Ratio in Aqueous PZT Tape Casting

  • Yoon, Seok-Jin;Shin, Hyo-Soon;Lee, Dong-Kyun;Kang, Chong-Yun;Park, Ji-Won;Kim, Hyun-Jai
    • The Korean Journal of Ceramics
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    • v.7 no.1
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    • pp.16-19
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    • 2001
  • For the fast dry of the aqueous tape, the process which water was reaplaced by organic solvent was proposed. Socalled, it was the solvent washing dry. Three organic solvents (methanol, ethanol and acetone) were selected for the washing solvent. The weight loss of the washed tapes was measured to evaluate the dry rate of the tapes and dried tapes were examined the generation of the cracks with the variations of the organic solvent and the washing time. Methanol, ethanol and acetone were available organic solvents for this method. The tapes washed in methanol, ethanol and acetone were dried rapidly for twenty minutes. After thirty minutes, the weight losses were not found any more, The solvent of the lower surface tension can decreases the crack of dried tape. If solvent substitutes water completely, though it was fast dried, crack can be eliminated.

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Fabrication of Li2ZrO3 Membrane and Evaluation on the Mechanical Properties Before and After CO2 Separation (Li2ZrO3 분리막의 제조와 이산화탄소 선택투과 전후의 기계적 특성 평가)

  • Park, Sang-Hyun;Lee, Shi-Woo;Yu, Ji-Haeng;Woo, Sang-Kuk;Lee, Kee-Sung
    • Journal of the Korean Ceramic Society
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    • v.44 no.1 s.296
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    • pp.58-64
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    • 2007
  • In this study, we investigated $Li_2ZrO_3$ membrane as a candidate material for high-temperature $CO_2$ separation and evaluated mechanical property. $Li_2ZrO_3$ powder was synthesized by solid state reaction of $Li_2CO_3\;and\;ZrO_2$. Then we fabricated $Li_2ZrO_3$ tape using tape casting method. Dense $Li_2ZrO_3$ membrane prepared by sintering at $1600^{\circ}C$ for 2 h after pressing $Li_2ZrO_3$ tape using lamination machine. Mechanical properties before and after $CO_2$ absorption of fabricated $Li_2ZrO_3$ membrane such as Hertzian indentation, Victors hardness and 3-point bending testing were evaluated.

MARGINAL FIT RELATED TO MARGIN TYPES OF GLASS INFILTRATED ALUMINA CORE FABRICATED FROM AQUEOUS-BASED ALUMINA TAPE

  • Oh, Nam-Sik;Yu, Byeung-Su;Kim, Il-Kyu;Choi, Jin-Ho;Kim, Dae-Joon;Park, Il-Seok;Lee, Myung-Hyun;Lee, Keun-Woo
    • The Journal of Korean Academy of Prosthodontics
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    • v.40 no.3
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    • pp.262-268
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    • 2002
  • Statement of problem. In-Ceram system is one of the all-ceramic crowns that can be used in anterior 3 unit fixed partial dentures and posterior single crowns. The alumina core used in In-Ceram system is manufactured using slip-casting technique. The slip-casting technique is difficult and technique sensitive. To improve this problem, tape-casting method was introduced into dentistry. There were no studies to examine the effect of margin design on the margin fitness of all-ceramic crowns fabricated from alumina tape. Purpose. The purpose of this study was to compare the marginal fitness of glass infiltrated alumina core fabricated from aqueous-based alumina tape according to different margin types ($90^{\circ},\;110^{\circ},\;135^{\circ}$ shoulder margin). Material and method. Three upper central resin incisors were prepared with $90^{\circ},\;110^{\circ}$, and $135^{\circ}$ shoulder margins for all-ceramic crowns, respectively. The resin teeth were duplicated and master die and special plaster die were made as usual. After alumina cores were fabricated from aqueous-based alumina tape, cores were cemented to each 15 epoxy dies replicated from three resin teeth with resin cement. These cemented cores were embedded in epoxy resin. Specimens were cut mesiodistally and buccolingually. Marginal gap and discrepancy were measured under microscope. Results. The marginal gap and discrepancy of $90^{\circ}$ marginal angle was $75.1{\mu}m,\;86.6{\mu}m,\;110^{\circ}$ marginal angle was $41.5{\mu}m,\;50.7{\mu}m$ and $135^{\circ}$ marginal angle was $51.7{\mu}m,\;54.2{\mu}m$, respectively. The smallest value was seen in 110 (angle, which was statistically significant compared to that of $90^{\circ}$ angle (p<0.05). Conclusion. Marginal fitness of alumina cores made of alumina tape with $110^{\circ}$ shoulder margin was best and others were clinically acceptable.

Enhanced Performance of La0.6Sr0.4Co0.2Fe0.8O3-\delta (LSCF) Cathodes with Graded Microstructure Fabricated by Tape Casting

  • Nie, Lifang;Liu, Ze;Liu, Mingfei;Yang, Lei;Zhang, Yujun;Liu, Meilin
    • Journal of Electrochemical Science and Technology
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    • v.1 no.1
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    • pp.50-56
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    • 2010
  • $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-\delta}$ (LSCF) powders with different particle sizes, synthesized through a citrate complexation method and a gel-casting technique, are used to fabricate porous LSCF cathodes with graded microstructures via tape casting. To create porous electrodes with desired porosity and pore structures, graphite and starch are used as pore former for different layers of the graded cathode. Examination of the microstructures of the as-prepared LSCF cathode using an SEM revealed that both grain size and porosity changed gradually from the catalytically active layer (near the electrodeelectrolyte interface) to the current collection layer (near the electrode-interconnect interface). Impedance analysis showed that a 3-layer LSCF cathode with graded microstructures exhibited much-improved performance compared to that of a single-layer LSCF cathode, corresponding to interfacial resistance of 0.053, 0.11, and 0.27 $\Omega{\cdot}cm^2$ at 800, 750, and $700^{\circ}C$ respectively.

Cold Rolling Process for the Matrix Fabrication of the Mcfc (용융탄산염형 연료전지의 전해질 매트릭스에 관한 연구)

  • Park, Sang-Kill;Rho, Chang-Joo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.27 no.2
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    • pp.125-131
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    • 1991
  • Electrolyte matrix fabrication process can be classifed as hot pressing, tape casting, callendering, electrophoretic deposition. however, these have limits in practice. Hot pressing is cumbersome method, because of careful heating and cooling. Furthermore, the perfected tile is so fragile that it is difficult to fit in a cell. Therefore this method is not adequate for mass production of the electrolyte matrix. Using electrophoretic deposition method, a very thin matrix can be made, but many attempts of the electrolyte embeding were found to be failure. Tape casting and callendering methods are employed in most of the matrix fabrication for the present. But these methods require lots of water as a solvent, so that coating of the LiAlO sub(2) with electrolyte is difficult. Recently, hot roll milling method has been developed and the perfected matrix was proved to be free from crack. The method, however, needs a roller to make a matrix and a perfected matrix is carefully striped off from the cooled roller. Therefore, this method requires a long time due to the cooling process. The author proposes a cold rolling process. On this method, heated slurry of the LiAlO sub(2) mixed with binder, is rolled with a cold roller. The heated slurry dose not adhere to the roller, since contacted hot slurry is rapidly solidified. Therefore fabrication speed is increased, without getting rid of merits of the hot rolling process.

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The Manufacturing and Analysis of Planar Dielectric materials for Integrated LC Resonant Module (집적 LC공진 모듈용 평판 유전체의 제조와 물성)

  • Park, Woo-Young;Kim, Jong-Ryung;An, Yong-Woon;Oh, Young-Woo;Kim, Hyun-Sik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.497-501
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    • 2003
  • In order to manufacture ceramic capacitors for the industrial electronic parts application using Tape casting method, the dielectric properties as a functions of sintering temperatures and the fabrication conditions of green sheet were investigated to consider the possibility of applications. When the mixing ratio of powder and solvent in slurry was 65:35, the uniform and dense green sheets was obtained. The dielectric constant was increased as the sintering temperature Over 94% of relative density and high were obtained to the specimens sintered at $1000^{\circ}C$. We can find that the device sintered at higher temperature than $1000^{\circ}C$ showed the relative density over 94% and the dielectric constant over 2000.

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Fabrication of Electrostatic Chucks Using Borosilicate Glass Coating as an Insulating Layer (붕규산염 유리를 절연층으로 도포한 정전척의 제조)

  • Bang, Jae-Cheol;Lee, Ji-Hyung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.390-393
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    • 2001
  • This study demonstrated the feasibility of tape casting method to fabricate soda borosilicate glass-coated stainless steel electrostatic chucks(ESC) for low temperature semiconductor processes. The glass coatings on the stainless steel substrates ranged from $100{\mu}m$ to $150{\mu}m$ thick. The adhesion of the glass coatings was found to be excellent such that it was able to withstand moderate impact tests and temperature cycling to over $300^{\circ}C$ without cracking and delamination. The electrostatic clamping pressure generally followed the theoretical voltage-squared curve except at elevated temperatures and higher applied voltages when deviations were observed to occur. The deviation is due to increased leakage current at higher temperature and applied voltage as the electrical resistivity drops.

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Fabrication of Electrostatic Chucks Using Borosilicate Glass Coating as an Insulating Layer (붕규산염 유리를 절연층으로 도포한 정전척의 제조)

  • 방재철;이지형
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.390-393
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    • 2001
  • This study demonstrated the feasibility of tape casting method to fabricate soda borosilicate glass-coated stainless steel electrostatic chucks(ESC) for low temperature semiconductor processes. The glass coatings on the stainless steel substrates ranged from 100 $\mu\textrm{m}$ to 150 $\mu\textrm{m}$ thick. The adhesion of the glass coatings was found to be excellent such that it was able to withstand moderate impact tests and temperature cycling to over 300$^{\circ}C$ without cracking and delamination. The electrostatic clamping pressure generally followed the theoretical voltage-squared curve except at elevated temperatures and higher applied voltages when deviations were observed to occur. The deviation is due to increased leakage current at higher temperature and applied voltage as the electrical resistivity drops.

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