Pore structure control of Si3N4 ceramics based on particle-stabilized foams

Porous Si3N4 ceramics with open, closed pores and nest-like structures were prepared by direct foaming method, and the stability of bubbles and the microstructures of sintered Si3N4 foam ceramics were investigated. The bubbles produced by short-chain amphiphiles have higher stability as compared with that produced by long-chain surfactants. Si3N4 ceramic foams using short-chain amphiphiles are particle-stabilized one, porous Si3N4 ceramics with open and closed pores can be easily prepared with this method, and the nest-like microstructure in Si3N4 foam ceramics is achieved at high gas-pressure sintering conditions. The decrease of flexural strength due to the increase of porosity can be weakened by decreasing pore size.