• Journal of the Microelectronics and Packaging Society
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• v.23 no.2
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• pp.11-18
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• 2016

This study focused on examining the possibility for recycling of Fe-Si electric sheet. We manufactured Fe-6.5Si mother alloy using by Fe-Si electric sheet scrap for transformer core materials. And then, soft magnetic alloy powder which diameter and shape were $45{\sim}150{\mu}m$ and sphere type was prepared by gas atomization process. As we compared to commercial Fe-6.5Si powder, its diameter distribution and microstructure of recycled powder was a similar. To investigate the possibility of reusing the soft magnetic composite sheet for electronics, recycled powder was treated to have a high aspect ratio (AR), and we finally obtained the 65~66 AR and $2.3{\mu}m$ thickness powder. To release the residual stress of powder, heat treatment was conducted under $300{\sim}400^{\circ}C$, $N_2$ gas. And then, soft magnetic sheet was made by tape casting process using by those powders. After the density and permeability of tape was measured, and we confirmed that the recycled Fe-Si electric sheet scrap was possible to reuse the soft magnetic materials of electronics.

• Journal of the Korean Ceramic Society
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• v.34 no.10
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• pp.1083-1091
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• 1997

As one of the chemical powder fabrication methods, the powder preparation method by using oxalate has the following advantages; (1) easy to control the chemical stoichiometry, (2) easy to fabricate homogeneous and fine particles, and (3) easy to be thermaly decomposed at low temperature. In the present study, the initial morphology and size distribution of the powder were controlled and the homogeniaty was improved. By carefully controlling the pH with NH4OH, the Bi(Pb)-Sr-Ca-Cu-O superconducting powders were prepared and investigated for their properties. The microstructures and the superconducting properties of the pelletized samples were investigated. Also, the microstructures and electrical properties of the samples prepared by tape casting method were investigated. The fabricated powders were spherical with less than 400 nm, but most of them were agglomerated to be 1~3 ${\mu}{\textrm}{m}$ in size. The critical temperature of the pelletized sample annealed at 84$0^{\circ}C$ for 72 hours in air was 110K. And the critical currents of annealed samples in air prepared by tape casting process for 24 hours and 72 hours were 0.6 A (Jc=600A/$\textrm{cm}^2$) and 1.9A (Jc=1, 900A/$\textrm{cm}^2$) respectively.

• Resources Recycling
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• v.26 no.5
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• pp.22-28
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• 2017

In-Bi-Sn alloy sheet has been used as a thermal fusible parts of secondary battery safety system. This study offers a simple process to make In-Bi-Sn alloy fusible parts. The process consists of two procedures, melting and sheeting by tape casting. 62.5 wt%-In 20.0 wt%-Bi 17.5 wt%-Sn (M.P. $92.4^{\circ}C$) alloy sheet obtained by tape casting was used as the thermal fusible sheet of thermal fuse system for mobile telephone. The performance test of the system was carried out in oil bath, and the fusible alloy sheet was melted and cut off at $95^{\circ}C$. This results confirmed the possibility that the alloy sheet obtained by tape casting can be usable as a thermal fusible parts of battery safety system. And this process can be applied as a simple process to recycle the In-Bi-Sn alloy scrap separated from the used thermal fuse system.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.138.2-138.2
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• 2010

Scandium-doped zirconium, ScSZ-based electrolyte, provides higher oxygen conductivity than YSZ and nano-based electrolyte materials are ideal for fabricating thin film electrolyte membrane of SOFC unit cell. Moreover, it may be applied to anode and cathode as well as electrolyte as ionic conductor. In this report, nano-based ScSZ-based electrolyte powder was prepared by co-precipitation synthesis. The particle size, surface area and morphology of the powder were observed by SEM and BET. Thin film electrolyte of under $10{\mu}m$ was fabricated by tape casting and co-firing using the synthesized ScSZ-based powders, and ionic conductivity and gas permeability of electrolyte film were evaluated. Finally, the SOFC unit cell was fabricated using the anode-supported electrolyte prepared by a tape casting method and co-sintering. Electrochemical evaluations of the SOFC unit cell, including measurements such as power density and impedance, were performed and analyzed.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.299-302
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• 2009

Oxygen ionic conductors of YSZ electrolyte in SOFC unit cell are applied to anode and cathode as well as electrolyte to have triple-phase-boundaries(TPB) of electrochemical reaction, and it is required to decrease the sintering temperature of anode-supported electrolyte by the nanoscale of YSZ powder.In this report, nanoscale YSZ powder was synthesized by the chemical co-precipitation method. The particle size, surface area and morphology of the powder were observed by SEM and BET. Thin film electrolyte of under 10㎛ was fabricated by tape casting using the synthesized YSZ powder, and ionic conductivity and gas permiability of electrolyte film were evaluated. Finally, the SOFC unit cell was fabricated using the anode-supported electrolyte prepared by a tape casting method and co-sintering. Electrochemical evauations of the SOFC unit cell, including measurements such as power density and impedance, were performed and analyzed.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.295-298
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• 2009

Oxygen ionic conductors of CeScSZ electrolyte in SOFC unit cell are applied to anode and cathode as well as electrolyte to have the triple-phase-boundaries of electrochemical reaction, and it is required to decrease the sintering temperature of anode-supported electrolyte by the nanoscale of CeScSZ electrolyte powder. In this report, nanoscale CeScSZ electrolyte powder was synthesized by chemical synthesis method. The particle size, surface area and morphology of the powder were observed by SEM and BET. Thin film electrolyte of under $10{\mu}m$ was fabricated by tape casting using the synthesized CeScSZ electrolyte powder, and ionic conductivity and gas permeability of electrolyte film were evaluated. Finally the SOFC unit cell was fabricated using the anode-supported electrolyte prepared by a tape casting method and co-sintering, in which the active layer, measuring $20{\mu}m$, was introduced in the anode layer to provide a more efficient reaction. Electrochemical evaluations of the SOFC unit cell, including measurements such as power density and impedance, were performed and analyzed.

• Journal of Powder Materials
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• v.22 no.6
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• pp.438-442
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• 2015

Porous thick film of alumina which is fabricated by freeze tape casting using a camphene-camphor-acrylate vehicle. Alumina slurry is mixed above the melting point of the camphene-camphor solvent. Upon cooling, the camphene-camphor crystallizes from the solution as particle-free dendrites, with the $Al_2O_3$ powder and acrylate liquid in the interdendritic spaces. Subsequently, the acrylate liquid is solidified by photopolymerization to offer mechanical properties for handling. The microstructure of the porous alumina film is characterized for systems with different cooling rate around the melting temperature of camphor-camphene. The structure of the dendritic porosity is compared as a function of ratio of camphene-camphor solvent and acrylate content, and $Al_2O_3$ powder volume fraction in acrylate in terms of the dendrite arm width.

• Journal of the Korean Ceramic Society
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• v.43 no.12 s.295
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• pp.788-797
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• 2006

An anode-supported SOFC single cell having $5{\mu}m$ thin electrolyte was fabricated cost-effectively by tape casting, laminating, and co-filing of anode (NiO-YSZ), cathode (LSM-YSZ), and electrolyte (YSZ) components. The optimal slurry compositions of the green tapes for SOFC components were determined by an analysis of the mean diameter, the slurry viscosity, the tensile strength/strain of the green tapes, and their green microstructures. The single cells with a dense electrolyte and porous electrodes could be co-fired successfully at $1325\sim1350^{\circ}C$ by controlling the contents of pore former and the ratio of coarse YSZ and fine YSZ in the anode and the cathode. The single cell co-fired at $1350^{\circ}C$ showed $100.2mWcm^{-2}$ of maximum power density at $800^{\circ}C$ but it was impossible to apply it to operate at low temperature because of low performance and high ASR, which were attributed to formation of the secondary phases in the cathode and the interface between the electrolyte and the cathode.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.169-172
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• 2002

This study demonstrated the feasibility of using tape-casting followed by sintering as a low-cost alternative for coating glass-ceramic or glass film on a metal substrate. The process has been successfully used to fabricate a glass-on-stainless steel and a glass-ceramic-on-molybdenum electrostatic chuck(ESC) with the insulating layer thickness about $150{\mu}{\textrm}{m}$. Electrical resistivity data of the coaling were obtained between room temperature and 55$0^{\circ}C$; although the resistivity values dropped rapidly with increasing temperature in both coatings, the glass-ceramic still retained a high value of $10^{10}$ ohm-cm at $500^{\circ}C$. Clamping pressure measurements were done using a mechanical apparatus equipped with a load-cell at temperatures up to $350^{\circ}C$ and applied voltages up to 600V; the clamping behavior of all ESCs generally followed the voltage-squared curve as predicted by theory. Based on these results, we believe that we have a viable technology for manufacturing ESCs for use in reactive-ion etch systems.

• 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.