2001 Fiscal Year Final Research Report Summary
Fabrication and Property Control of Ceramic Composites for High Temperature Filtration
| Project/Area Number |
12450348
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
無機工業化学
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
TAKAHASHI Junichi Hokkaido Univ., Grad. School of Eng., Asso., Prof., 大学院・工学研究科, 助教授 (40110259)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIKAWA Tadahiro Nagoya Institute of Technol., Dept of Eng., Asso., Prof., 工学部, 助教授 (70135408)
OTA Toshitaka Nagoya Institute of Technol., Ceram. Res. Lab., Prof., セラミックス基盤工学研究センター, 教授 (30135412)
TAKAHASHI Minoru Nagoya Institute of Technol., Ceram. Res. Lab., Prof., セラミックス基盤工学研究センター, 教授 (60093100)
SUZUKI Hisao Shizuoka Univ., Dept of Eng., Asso., Prof., 工学部, 助教授 (70154573)
ITOH Hidenobu Kitami Institute of Technol., Dept of Eng., Asso., Prof., 工学部, 助教授 (90113703)
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| Project Period (FY) |
2000 – 2001
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| Keywords | High Temperature Filter / Ceramics / Porous Materials / High Temperature Properties / Mechanical Property / Fabrication Process / Microstructure |
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| Research Abstract |
Porous cordierite/mullite (C/M) composite and cordierite ceramics were fabricated using gel-casting as forming method. In order to control the morphology of pores and increase the porosity in the C/M composite bodies, spherical corn starch particles with 10μm in diameter was added to a slurry containing fixed amounts of the composite powder, organic monomer and dispersant. After in-situ solidification of the slurry (polymerization of the monomer added) in a mold, a green body was heated up to 700℃ (binder born-out) and successively sintered at 1350℃ for 10 h in air, which produced a Porous C/M composite having 54 % porosity. Although the porosity of the sintered composites was considerably decreased with an increasing sintering temperature, only a subtle change was detected in the average size of the primary pores (0.4 - 0.6 μm) formed between starting composite particles. Concerning the secondary pores derived from corn starch particles, spherical pores with the diameter of about 10 μ
… More
m corresponding to the original shape and size of the starch powder added were observed in C/M composites obtained at 1350℃. At elevated sintering temperatures, the secondary pores were deformed into irregularly shaped and smaller ones. Therefore, an optimum sintering temperature to control the resulting pore structure was found to be 1350℃ for the present composite powders.
N_2 gas bubbling procedure was employed to produce highly porous cordierite ceramics from a commercial powder. Prior to the solidification due to polymerization, a constant flow of N_2 gas was introduced into a slurry. This procedure yielded extremely porous alumina ceramics with 75 - 83 % porosity. Bending strength of these samples ranged between 3 - 10 MPa, which were higher than those of cordierite ceramics fabricated using organic pore-forming agents. The enhanced strength might be due to the characteristic pore structure in which largely spherical pores derived from N_2 gas bubbling were interconnected.
Porous alumina ceramics were also fabricated using some forming procedure other than gel-casting. Relationships between pore structures and mechanical or thermal properties were examined for samples that particles of spherical hollow glass, PVA or various kinds of starches were added as pore-forming agent. Less
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