通过凝胶注模成型和无压烧结制备碳化硅陶瓷  

Preparation of Silicon Carbide Ceramics by Aqueous Gelcasting and Pressureless Sintering

作　　者：张景贤[1] 江东亮[1] 林庆玲[1] 陈忠明[1] 黄政仁[1] 

机构地区：[1]高性能陶瓷和超微结构国家重点实验室,中国科学院上海硅酸盐研究所,上海200050

出　　处：《硅酸盐学报》2012年第8期1154-1157,共4页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(50990301,51072210)资助项目

摘　　要：以四甲基氢氧化铵为分散剂,糊精为碳源,通过静电稳定作用,制备了高固相含量、分散良好的碳化硅陶瓷浆料。以水溶性N,N–二甲基丙烯酰胺为单体,N,N’–亚甲基双丙烯酰胺为交联剂,采用实验室开发的偶氮[2–(2–咪唑啉–2–基)]丙烷HCl引发体系,在45～50℃引发单体聚合,制备出水基凝胶注模碳化硅素坯,素坯的相对密度达58%,抗弯强度大于40MPa。进一步通过无压烧结制备相对密度高于98%,硬度达28GPa,强度达530 MPa的SiC陶瓷。对素坯和SiC陶瓷的微结构和力学性能进行了测试和表征。结果表明:采用糊精作为碳源可以提高凝胶注模浆料的分散性,避免凝胶过程中的碳阻聚问题,有利于制备出高性能的碳化硅陶瓷材料。SiC slurries with a high solid content were prepared via electrostatic stabilization mechanism using tetramethylammonium hydroxide as dispersant and dextrin as carbon source. After adding dimethylacrylamide and N,N＇-methylenebisacrylamide as mono- mer and crosslinker, respectively, the slurries were gelified in the temperature range of 45-50℃ using a self-made azobis [2-（2-imidazolin-2 yl） propane] HCl initiator system. After drying, the relative density and bending strength of SiC green body can reach 58% and 40 MPa, respectively. Silicon carbide ceramics with the relative density, hardness and strength as high as 98%, 28 GPa and 530 MPa respectively can be obtained by a pressureless sintering. The microstructure and mechanical properties of green and as sintered SiC samples were characterized. The results show that the proposed SiC slurry system using dextrin as the carbon source has the advantage of improving the dispersibility of the slurries and avoiding the polymerization inhibition effect of carbon, which is thus effective for the preparation of high performance SiC ceramics.

关 键 词：凝胶注模成型 碳化硅 浆料 无压烧结 

分 类 号：TQ174[化学工程—陶瓷工业]