Low-Temperature Sintering of SiC Reticulated Porous Ceramics Using Al2O3-SiO2 as Sintering Aids

Abstract

Currently, one of the most popular methods for the production of reticulated porous ceramics (RPCs) is the polymer sponge method, which was invented by Schwartzwalder and Somers. SiC RPCs can be fabricated by using the A12O3-SiO2 as sintering aids at low temperature as 1200-1300 °C in cases with SiC (20-50 % (mass percent)). However, when the content of SiC powders (relative to total weight of solids) was higher than 50 % (mass percent), the most suitable sintering temperature was higher than 1400 °C. In this work, SiC reticulated porous ceramics (SiC RPCs) was fabricated via the polymer sponge method using Al2O3-SiO2 as sintering aids at 1100-1500 °C. In order to obtain SiC RPCs with optimized mechanical performance, the properties of the slurry and influence of sintering temperature have been investigated. It was found that, rheological properties, solid content of the slurry and sintering temperature all have influence on the physical and mechanical properties of SiC RPCs. In order to achieve optimal properties of SiC RPCs, the optimal pH value ,solid content, sintering temperature and content of silica fume were 11, 73.4 % (mass percent), 1300 °C and 17 % (mass percent), respectively.