Gelcasting preparation of porous silicon nitride ceramics by adjusting the content of monomers

The gelcasting preparation of high-performance porous Si3N4 ceramics by merely increasing monomer content in the slurry without other organic additives was presented, and the influences of monomer content and the ratio of monomers on gelcasting preparation of porous Si3N4 ceramics were investigated. The results suggest that monomer content and the ratio of monomers have great influences on the performances of green body and sintered body of porous Si3N4 ceramics, and the warpage and shrinkage of green body can be effectively improved by selecting reasonable the ratio of monomers. High-performance sintered body was achieved by high-performance green body. The pore size of porous Si3N4 ceramics is less than 1 mu m, and the flexural strength and porosity are above 130 MPa and above 50%, respectively.