Fabrication and Property Control of Ceramic Composites for High Temperature Filtration

高温过滤陶瓷复合材料的制备及性能控制

• 批准号: 12450348
• 负责人: TAKAHASHI Junichi
• 金额: $ 8.7万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12450348/
• 关键词: High Temperature Filter; Ceramics; Porous Materials; High Temperature Properties; Mechanical Property; Fabrication Process; Microstructure; セラミックコンポジット; コージェライト; ムライト; 粉体プロセッシング; 高温腐食

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

采用凝胶注模成型方法制备了多孔堇青石/莫来石（C/M）复合材料和堇青石陶瓷。为了控制C/M复合体的孔隙形态并增加孔隙率，将直径10μm的球形玉米淀粉颗粒添加到含有固定量的复合粉末、有机单体和分散剂的浆料中。浆料在模具中原位固化（添加的单体聚合）后，将生坯加热至700℃（粘结剂脱模），并在空气中于1350℃下连续烧结10小时，制得孔隙率为54%的多孔C/M复合材料。尽管随着烧结温度的升高，烧结复合材料的孔隙率显着降低，但在起始复合材料颗粒之间形成的初级孔隙的平均尺寸（0.4-0.6μm）仅检测到细微的变化。对于源自玉米淀粉颗粒的次生孔，在1350℃获得的C/M复合材料中观察到直径约为10μm的球形孔，与添加的淀粉粉末的原始形状和尺寸相对应。在升高的烧结温度下，次生孔变形为形状不规则且较小的孔。因此,对于本复合粉末来说,控制最终孔隙结构的最佳烧结温度为1350℃。采用N_2鼓泡工艺从商业粉末中制备高孔堇青石陶瓷。在由于聚合而固化之前，将恒定流量的N_2气体引入浆料中。该过程产生了孔隙率高达 75 - 83% 的极其多孔的氧化铝陶瓷。这些样品的弯曲强度在3-10 MPa之间，高于使用有机成孔剂制造的堇青石陶瓷。强度的提高可能是由于其特征性的孔结构，其中由N_2气体鼓泡产生的大部分球形孔相互连接。除了凝胶注模之外，还使用一些成型工艺制备了多孔氧化铝陶瓷。研究了添加球形空心玻璃、PVA或各种淀粉颗粒作为造孔剂的样品的孔结构与机械或热性能之间的关系。较少的