水基冷冻干燥工艺制备莫来石结合多孔SiC陶瓷  

Fabrication of Mullite Bonded Porous SiC Ceramics by Freeze-drying of Aqueous Slurries

作　　者：梁森[1] 徐照芸[1] 罗民[1] 高忙忙[1] 梁斌[1] 

机构地区：[1]宁夏大学化学化工学院光伏材料重点实验室,银川750021

出　　处：《硅酸盐通报》2015年第12期3456-3461,共6页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金项目(21061012);宁夏自然基金项目(NZ13013)

摘　　要：以微米级SiC和纳米级α-Al_2O_3为原料,经水基冷冻干燥及原位反应烧结工艺制备莫来石结合多孔SiC陶瓷。XRD分析表明多孔陶瓷主相是α-SiC,结合相是莫来石。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3~20μm,小孔孔径峰值为0.5~1μm。体系中SiC固相含量及烧结温度对多孔陶瓷显微结构及性能有显著影响。当SiC固相含量由20vol%增至30vol%时,多孔陶瓷的孔结构由间距为20~30μm、且定向排列的层状结构演变为孔径约为4μm的定向通孔结构。当烧结温度由1200℃升至1500℃时,多孔SiC陶瓷开气孔率由66%下降至64%,抗压缩强度由4.5 MPa升至16 MPa。Using sub-micrometer SiC and nano-α-Al2O3 as raw materials,mullite bonded porous SiC ceramics were fabricated by combined freeze drying of aqueous slurries with in-situ reactive sintering technique. The XRD results showed that the main phase was α-SiC,the bonded phase was mullite. The pore diameter of porous ceramics ranged from 3 μm to 20 μm,and the diameter of small pore was in the range of 0. 5-1 μm. The microstructure and properties depended on the content of SiC and sintering temperature. When the SiC content increased from 20vol% to 30vol%,the distance between holes was20-30 μm,and a directional-alignment-layerd structure changed into directional- via holes structure and the pore size was about 4 μm. Meanwhile,the porosity decreased from 66% to 64%,and compressive strength increased from 4. 5 MPa to 16 MPa when the sintering temperature increased from 1200 ℃ to1500 ℃.

关 键 词：多孔SiC陶瓷 冷冻干燥法 原位反应烧结 莫来石结合 

分 类 号：TQ174[化学工程—陶瓷工业]