摘要
采用有机泡沫浸渍工艺制备了碳化硅基网眼多孔陶瓷．研究了真空脱气处理对浆料流变特性和烧结体的力学性能及显微结构的影响．结果表明；脱气处理改善了浆料的流变特性，使浆料在有机泡沫体上的涂覆量增加和结构均匀性得到改善；压汞仪测试数据和ＳＥＭ观察表明脱气处理明显地消除了孔筋内的孔径为１００μｍ左右的大气孔；经脱气处理后，材料的抗弯强度从２．３４ＭＰａ提高到３１８ＭＰａ．脱气处理对网眼陶瓷强度的改善主要来自两方面的贡献：一是相对密度的增加，二是孔筋中大气孔的消除，但后者是最主要的贡献，这个结果与目前建立的开孔陶瓷泡沫的力学模型吻合得很好．
SiC based reticulated porous ceramics (RPCs) were fabricated from ceramic slurries by the replication process with polyurethane sponges as the templates. Effect of degassing on the rheological behavior of the slurry and mechanical property of RPCs was investigated in detail. The rheological behavior of the slurry was improved by degassing, which improved the loading of the slurry on the sponge and large-scale uniformity of RPCs. The number of pores of approximately 100 mum in the struts was reduced significantly by degassing, which was confirmed by scanning electron microscopy (SEM) observation and Hg porosimetry. Flexural strength of RPCs increases from 2.34 to 3.18MPa after degassing. Improvement in the strength of RPCs by degassing is mainly due to the improvement of the strut strength, resulting from the significant decrease of the large defects in the struts. In addition, a slight increase in the relative density has a contribution to the increase of the strength. The results are in good agreement with the theoretical model of the mechanical behavior of open cell ceramics.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2001年第5期889-895,共7页
Journal of Inorganic Materials
