FINE POROUS CERAMICS AND MANUFACTURE THEREOF

摘要

PURPOSE: Provided is a manufacturing method of porous ceramics having homogeneous fine pores and good strength without extra process and equipment by using non-critical fluid as a medium for forming pores. CONSTITUTION: The manufacturing method of porous ceramics comprises the steps of: mixing more than 50wt.% of polymer ceramic precursor powder(<=50micrometer) such as polycarbosilane, polysiloxane and polysilazane with less than 50wt.% of ceramic powder such as Al2O3, Y2O3, SiC and SiN4, and optionally less than 5wt.% of hardeners such as aluminum acetyl acetonate and triethylene diamine, wherein the amount of ceramic precursor is based on the total amount of starting materials; forming; putting compacts in a pressure vessel and flowing non-critical fluid, CO2(20-400atm.), to saturate the compacts with CO2; reducing pressure of the vessel for supersaturating CO2 in the compacts; heating between softening and melting points of polymer ceramic precursors to erupt CO2 for forming pores; hardening; and thermal treating at 1600-1900deg.C in inert or air atmosphere.