摘要
以微米级SiC粉体为原料,利用冷冻干燥和原位反应烧结制备了具有层状孔道结构的SiC多孔陶瓷。XRD分析表明多孔陶瓷的主相是α-SiC,结合相是方石英;SEM观察到多孔陶瓷具有相互连通的开孔结构;多孔SiC陶瓷的总孔隙率和开孔隙率随固相含量和烧结温度的增加而下降。多孔陶瓷的孔径分布呈现双峰分布特点,大孔孔径峰值介于20～80μm,小孔孔径峰值为0.5～0.9μm。在原位反应烧结过程中,在1100℃以上SiC开始发生氧化形成SiO2结合的多孔SiC陶瓷,显著提高了陶瓷的压缩强度。随着烧结温度从1000℃提高到1500℃,固相含量为30vol%的多孔SiC陶瓷开孔率从68.9%下降到61.8%,压缩强度由5.5 MPa升至25.5 MPa。
Porous oxidation-bonded silicon carbide ceramics with highly aligned laminated structures were fabricated by combined freeze-casting of aqueous slurries with oxidation-bonding sintering technique. The different parameters of the process, such as the solids content of the suspension, the sintered temperature have been studied to determine their influence on the microstructure, and distribution of pores of the sintered samples. The pore structure was substantially affected by the starting slurry concentration and sintering temperature. A porous silicon carbide with high porosity （50%-70%） was obtained and its porosity somewhat decreased when the slurry concentration and sintering temperature increased. The porous SiC ceramics sintering at 1400℃ had a unique microstructure. When the solid content was 30%, a high compressive strength up to 25.5 MPa was achieved at a high porosity of 61.8%.
出处
《硅酸盐通报》
CAS
CSCD
北大核心
2011年第3期736-740,共5页
Bulletin of the Chinese Ceramic Society
基金
国家自然科学基金项目(No.21061012)
国家教育部科学技术研究重点项目(No.210237)
宁夏自然科学基金(NZ0916)
