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SiOC porous ceramic has a series of excellent performance, makes its application more widely used, the methods for their preparation are constantly evolving. In this paper, on the basis of a comprehensive overview of Porous Ceramics Research, carried out a of silicone resin crosslinking self the foam prepared high porosity SiOC porous ceramic. First, the comparative analysis of the two types of silicone DC217 and DC249 foaming properties, selected carefully the silicon resin DC217 as crosslinked foam pioneer since. Compounding, molding, crosslinking the self-foaming and pyrolysis, prepared by high porosity SiOC porous ceramics, the effects of heating rate, the intermediate insulation, external pressure and types of filler (SiOC, SiC), the filler content and particle size factors such as the impact on the structure and properties of porous ceramic. Increased from 0.25 ℃ / min 3 ° C / min heating rate control crosslinked silicone content for 90vol% the SiOC micronized filler after the first increase of the porosity of the porous ceramic to reduce maximum 0.5 ℃ / min, total porosity and open porosity of 88.2% and 72.5%, respectively, compressive strength has been reducing. When crosslinking a heating rate of less than 1 ℃ / min, the pore structure of the porous ceramic presents a three-dimensional open mesh structure. Incubated at different temperatures (160 ° C, 190 ° C, 220 ° C), the impact on the morphology and size of the porosity of the resulting porous ceramic is large, but the improvement on compressive strength is not obvious. When the the silicon resin content of 70 vol% SiOC micronized for filler control external pressure from 1MPa to 4MPa, total porosity and open porosity of the porous ceramic decreased from 69.8% and 58.4% to 58.3% and 43.9%, anti- compressive strength increased from 3.9 MPa to 14.9MPa. Further, as the external pressure increases, the pore structure of the porous ceramics is becoming increasingly rules, pore size is also more consistent. When packing (SiOC Micropowder) content from 0vol.% Increased to 30 vol% total porosity and open porosity of the porous ceramic trends, are the first increases and then decreases, the compressive strength is reduced to increase. When the filler content is less than 30vol.%, The pore structure of the porous ceramic comparison rules, mostly rendered opening spherical characterized. Selection of SiC powder as a filler, in the case of external air pressure is not added, the pore structure of the resulting porous ceramic is poor. Crosslinked foam in the external pressure, the pore structure of the resulting porous ceramic is preferably under the same conditions, SiOC porous the pore structure of the ceramic powder as a filler resulting similar, but the oxidation resistance was significantly higher than the latter. Under pressurized conditions, control the particle diameter of the SiC powder from 5μm to 10μm, the porosity of the porous ceramic (total porosity and the opening ratio) increases, whereas the compressive strength is decreased. To continue to increase the particle diameter of the SiC powder, increases from 10μm to 15μm, the resulting porous ceramic porosity (total pore and open porosity), the average pore size and the compressive strength were little changed. The study showed that using a silicone resin crosslinking from foaming method can be prepared by a higher porosity the SiOC porous ceramic. The various process parameters by affecting the formation of bubbles in the polymer melt process, thereby affecting the pore structure of the porous ceramic. By precise control of process parameters to obtain the desired structure of the SiOC porous ceramics.
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