Low-temperature production of porous silicon-carbide ceramics by the self-binding method

Polycarbosilane (PCS) heat-treated (preheated) at low temperatures (500 – 600°C) was chosen as the raw material for the production of porous SiC ceramics. The PCS was ground in a ball mill, shaped by slip casting, and sintered at 1000°C. Due to the semi-organic structure of the preheated PCS, the milled powders can be shaped and then sintered at 1000°C without the use of other binders; this made possible to create the above-mentioned porous SiC ceramics. The pore size, open porosity, and ultimate flexural strength of the SiC ceramics that were obtained were studied. It was found that an increase in the temperature at which the PCS is heat-treated impedes its shaping and reduces the open porosity and ultimate flexural strength of the resulting SiC ceramics. Information is also presented from a study of the fracture surface of the porous SiC ceramic.