The invention relates to a preparation method of a silicon carbide porous ceramic with graphite as a pore forming agent and mullite as a bonding phase generated by in-situ reaction of silicon carbide surface. The utility model is characterized in that the silica generated by the partial oxidation of the silicon carbide surface is reacted with the alumina, and mullite is formed in situ to combine the silicon carbide particles. SiC: Al: 2 O: 3: 2: graphite: Y O: 3 = 1: 0.1 to 1: 0 to 1: 0 ~ 0.05 (weight ratio), phenolic resin and ethanol mixture after milling, drying, grinding, sieving, dry pressing then, firing in the air, get the mullite bonded porous SiC ceramics. The porous ceramic flexural strength can reach 20MPa, open porosity of 20 ~ 70%, 0.1 ~ 30 micron pore size, the volume density of 1 ~ 2.2g / cm = 3, the coefficient of thermal expansion of 6 ~ 9 * 10 = 6, K = 1, - (0 to 800 DEG C), can be used for liquid gas filter and high temperature and corrosive environment at room temperature, and the high temperature catalyst carrier material.
【技术实现步骤摘要】
本专利技术涉及一种原位反应法制备莫来石结合的碳化硅多孔陶瓷的方法,属于多孔陶瓷领域。
技术介绍
由于具有低体密度、高渗透率、高温性能稳定、耐酸碱腐蚀性好和良好的催化活性等优点,多孔陶瓷可广泛地用于过滤器材料、膜材料、催化剂载体、热绝缘材料、气体燃烧室介质和耐火材料。除了拥有上述多孔陶瓷的优点,碳化硅多孔陶瓷还具有低热膨胀系数、高热导和优异的机械性能,这使碳化硅多孔陶瓷具有广阔的应用前景,被认为是最理想的热气过滤材料之一。根据成孔工艺的不同,碳化硅多孔陶瓷的制备方法有颗粒堆积、添加造孔剂、发泡、有机泡沫浸渍、溶胶凝胶和前驱体法。Xinwen Zhu等人以聚氨酯泡沫为浸渍模板制备出网孔状的碳化硅多孔陶瓷(Xinwen Zhu,Dongliang Jiang,Shouhong Tan,preparation of silicon carbide reticlulatedporous ceramics,Materials Science and Engineering A323(2002)232~238),得到的碳化硅网孔陶瓷具有排列规则的连通孔隙,孔隙率高达93%, ...
【技术保护点】
一种原位反应制备莫来石结合的碳化硅多孔陶瓷的方法,包括原料选择、配比混合、双面干压成型以及烧结工艺,其特征在于以石墨为造孔剂、氧化钇为烧结助剂,SiC高温下氧化生成SiO↓[2],再由生成的SiO↓[2]直接与Al↓[2]O↓[3]颗粒原位反应生成莫来石,制备成莫来石结合的碳化硅多孔陶瓷。
【技术特征摘要】
【专利技术属性】
技术研发人员:丁书强,曾宇平,江东亮,
申请(专利权)人:中国科学院上海硅酸盐研究所,
类型:发明
国别省市:31[中国|上海]
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