醇–水混合溶剂凝胶注模制备SiC多孔陶瓷的工艺与性能  

The process and properties of porous SiC ceramics prepared by alcohol-water based on gel-casting process

作　　者：陈鑫[1] 李国栋[1] 熊翔[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2017年第2期284-291,共8页Materials Science and Engineering of Powder Metallurgy

基　　金：国家重点基础研究发展计划资助项目(2011CB605805);国家自然科学基金创新群体项目(51021063)

摘　　要：将SiC陶瓷粉末、醇-水混合溶剂、丙烯酰胺-亚甲基双丙烯酰胺凝胶体系以及堇青石-锂辉石复合烧结助剂配制成料浆,采用凝胶注模成型–烧结工艺制备SiC多孔陶瓷,研究烧结助剂用量和烧结温度对多孔SiC陶瓷的形貌与显微结构、物相组成以及强度、孔径、开孔率与渗透率等性能的影响。结果表明:温度高于1 300℃时,复合烧结助剂熔融形成固溶体,从而实现SiC多孔陶瓷的低温烧结;随烧结助剂用量增加或烧结温度升高,SiC多孔陶瓷的开孔率和气体渗透速率均下降。在料浆中SiC陶瓷粉体体积分数为20%、烧结助剂质量分数为10%、醇水体积比为7:3、锂辉石与堇青石质量比为2:1的条件下,于1 370℃烧结后得到的SiC多孔陶瓷,孔隙率高、孔径分布集中(4~15μm),孔形貌呈均匀的三维无规则贯通结构,抗弯强度为8.5 MPa,开孔率达到67.9%,透气率为280.5 m^3/(m^2·Pa·h)。The SiC slurry was prepared using ethanol-water mixed solvent as the dispersion medium, acrylamide-methylene bis acrylamide as gel system and cordierite-spodumene as sintering additives. The porous SiC ceramics were fabricated by gelcasting-sintering process. The effects of sintering additive content and sintering temperature on the morphology, microstructure, phase composition, strength, pore size, open porosity and gas permeability of the sintered porous SiC ceramics were investigated. The results show that, when the temperature is higher than 1300 ℃, sintering additives absorb heat and form the low-temperature melting solid solution, which can effectively decrease sintering temperature of the SiC porous ceramic. With increasing the content of sintering additive and sintering temperature, both the porosity and gas permeability of the porous SiC ceramics decrease. At conditions of 20% volume fraction of SiC powder in the slurry, 10% mass fraction of sintering additive, 7：3 volume ratio of alcohol-water 2： I mass ratio of spodumene and cordierite and sintering temperature of 1370 ℃, the pores morphology of porous SiC ceramics are three dimensional irregular penetrating structure, and the porosity, flexural strength, pore size and gas permeability of SiC porous ceramics are 67.9%, 8.5 MPa, 4-15 pm and 280.5 rn3/（m2＂Pa-h）, respectively.

关 键 词：SiC 多孔陶瓷 凝胶注模 堇青石 锂辉石 烧结助剂 

分 类 号：TQ174[化学工程—陶瓷工业]