Fabrication of Silicon Carbide Reticulated Porous Ceramics through Organic Foam Infiltration Process

摘要

Reticulated silicon carbide porous ceramics was fabricated through organic foam infiltration process by using silicon carbide slurry prepared from silicon carbide,alumina and clay and other raw materials.The effect of solid content on the viscosity and Zeta potential of the slurry were investigated.The results showed that the viscosity of slurry increased with the increase of the solid content.The absolute value of Zeta potential increased with the increase of pH value of the slurry from acid to alkaline aptitudes,and it became smaller with the further increase of the pH value.The maximum was reached at the pH around 10.The viscosity of slurry in the range of 4000mPa?s ～ 5000mPa?s was appropriate to prepare reticulated silicon carbide porous ceramics.The sintered body collapsed or cracked apparently,when the viscosity was too low.On the other hand,the viscosity could not be too high because it’s hard for slurry to impregnate foam.The performance of the samples coated once and recoated was compared.The porosity of the sample with one layer was higher than that of the samples with two layers.However,the recoating process improved the compressive strength and flexural strength of the reticulated silicon carbide porous ceramic.