• Journal of the Korean Ceramic Society
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• v.49 no.6
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• pp.625-630
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• 2012

Highly porous silicon carbide (SiC) ceramics were fabricated from polysiloxane, SiC and carbon black fillers, AlN-$Y_2O_3$ additives, and poly (ether-co-octene) (PEOc) and expandable microsphere templates. Powder mixtures with a fixed PEOc content (30 wt%) and varying SiC filler contents from 0-21 wt% were compression-molded. During the pyrolysis process, the polysiloxane was converted to SiOC, the PEOc generated a considerable degree of interconnected porosity, and the expandable microspheres generated fine cells. The polysiloxane-derived SiOC and carbon black reacted and synthesized nano-sized SiC with a carbothermal reduction during a heat-treatment. Subsequent sintering of the compacts in a nitrogen atmosphere produced highly porous SiC ceramics with porosities ranging from 78 % to 82 % and a flexura lstrength of up to ~7 MPa.

• Proceedings of the Membrane Society of Korea Conference
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• 1992.04a
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• pp.60-60
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• 1992

알루미나 분리막이 세라믹 분리막의 연구개발 초기단계부터 많은 사람들에 의해 연구되어온 반면, TiO$_2$ 및 ZrO$_2$ 분리막에 관한 연구는 상대적으로 관심이 적었고 따라서 그 내화학성및 투과특성의 우수함이 밝혀진 것도 최근의 일이다. TiO$_2$ 및 ZrO$_2$ UF 분리막의 제조방법으로는 $Al_2O_3$ 의 경우와 마찬가지로 대부분 졸-겔 공정이 이용되고 있다.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.10a
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• pp.87-89
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• 1997

The BaTiO$_3$ fine powder was prepared by hydrthermal method using titanium tetrahydoxide (Ti(OH)$_4$) and barium dihydroxide (Ba(OH)$_2$.8$H_2O$) as raw materials. The fine powder was obtained at temperatures as low as 160 to 185$^{\circ}C$. The properties of the BaTiO$_3$ powder were studied as a function of various parameters (reaction temperature, reaction time, Ba/Ti=ratio, etc). The average particle size of the BaTiO$_3$ increased with increasing reaction temperature. After hydrothermal treatment at 17$0^{\circ}C$ for 8 h, the average particle size of the BaTiO$_3$ powder was about 30 nm and the particle size distribution was narrow.

• Journal of the Korean Ceramic Society
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• v.22 no.6
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• pp.58-70
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• 1985

The bond strength of metal to ceramic sealing in Mo-Mn metallizing was investigated by examining the effects of flux composition in alumina ceramics particle size of molybdenum metal powder wet hydrogen atmosphere and temperature in metallizing. The maximum bond strength was obtained when the glass phase filled almost all the microstructural cavities around the interfacial area with few micropores. Such a favorable microstrcutre waas formed and maximum bond strength was observed between 130$0^{\circ}C$. Also the metal to ceramic bond strength was increased using finer molybdenum metal powder than coarse powder. When content of $SiO_2$ in the flux of alumina ceramics was constant metal to ceramic bond strength was improved with increasing the ratio of CaO to MgO in the flux.

• Membrane Journal
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• v.7 no.1
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• pp.11-14
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• 1997

Two membrane-rdated research projects are now being developed in Japan and their main target is to develop new inorganic membranes. The first project is the R & D of membranes for carbon dioxide recovery at high temperature, conducted by the Japan Fine Ceramics Center (JFCC) and Japan Fine Ceramics Association (JFCA) under the supervision by the New Energy and Industrial Technology Development Organization (NEDO). The second one is the R & D of membranes for petroleum refinery and chemical processes, conducted by the Japan High Polymer Center (JHPC) under the supervision by the Petroleum Energy Center (PEC). Cooperating with these projects researchers in many universities and research institutes have been publishing many interesting data of inorganic membranes manufactured by various methods. Many such results are summarized and reported.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.09a
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• pp.15-20
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• 1995

Two membrane-related research projects are now being developed in Japan and their main target is to develop new inorganic membranes. The first project is the R & D of membranes for carbon dioxide recovery at high temperature, conducted by the Japan Fine Ceramics Center (JFCC) and Japan Fine Ceramics Association (JFCA) under the supervision by the New Energy and Industrial Technologu Development Organization (NEDO). The second one is the R & D of membranes for petroleum refinery and chemical processes, conducted by the Japan High Polymer Center (JHPC) under the supervision by the Petroleum Energy Center (PEC). Cooperating with these projects researchers in many universities and research institutes have been publishing many interesting data of inorganic membranes manyfactured by various methods. Many such results are summarized and reported.

• Journal of the Korean Ceramic Society
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• v.44 no.5 s.300
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• pp.166-172
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• 2007

In this study, magnetic properties of the strontium ferrite were theoretically investigated by Ab initio (first principle) method. The influences of various additives on the magnetic properties of the strontium ferrite were analyzed to designed new composition of the strontium ferrite system with high magnetic characteristics. As shown in the results, the total magnetization of the strontium ferrite was $42.55M_B$. Based on the DOS results, the magnetic characteristics of the strontium ferrite were mainly influenced by Fe atoms at 6 positions in the unit cell. Also the La-Mn strontium ferrite has the superior magnetic property than the Mn strontium ferrite.

• Journal of the Korean Ceramic Society
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• v.32 no.5
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• pp.587-593
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• 1995

Abnomal grain growth behavior of BaTiO3 ceramics was investigated with addition of seed grains. It was foudn that the nucleation rate of abnormal grain was constant and growth of abnormal grain was linearly increased with sitnering time, regardless of amount of seed grains. These facts were also confirmed by fitting of the volume fraction of abnormal grain vs. sintering time using Avrami type equation (n=4). It was suggested that seed grains did not change the nucleation rate or growth mechanism of abnormal grain but increase the number of abnormal grains at initial stage of sintering and then it led to fine microstructure of BaTiO3 ceramics.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1121-1121
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• 2006

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.154.1-154
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• 2003