Preparation of Silicon Carbide Reticulated Ceramics
碳化硅网眼多孔陶瓷的制备

The open cell silicon carbide reticulated ceramics were prepared by impregnating a polyurethane sponge with aqueous ceramic slurry. TG-DTA analysis of the polyurethane sponge was used to determine the global thermal cycle for the consolidation of the porous ceramic bodies.A thixotropical slurry by adding effective rheological agents was optimized to uniformly coat the polyurethane sponge. The effect of processing conditions on properties of the sintered was studied.The effect of binders on processing was discussed in detail and it was found that colloidal silica is an effective binder. The structure of the sintered bodies were characterized by SEM and the phases of the sintered bodies were determined by XRD. Some properties including bulk density,strut density, porosity and strength of the sintered bodies, were characterized. The SiC reticulated ceramics, having 75%～85% porosity and bending strength as high as 2.5MPa, can be obtained under firing temperature 1450℃ for lh. The phases of the fired bodies are composed of α-SiC,α-Al2O3, cristobalite and mullite.