Preparation of Silicon Nitride Porous Ceramics

Abstract

A silicon nitride porous ceramics having excellent mechanical strength and dielectric properties can be employed as a wave-transparent material. The silicon nitride porous ceramic contains a plurality of silicon nitride crystal grains with pores formed in grain boundary which forms a three-dimensional network structure. The properties of the silicon nitride porous ceramics was studied , the porous ceramics was prepared by different process parameters, including the pressure of cold isostatic pressing, temperature of sintering and sintering atmosphere, etc.; A high porosity(>50%), high strength(>120MPa), low dielectric properties(ε<3.2) silicon nitride ceramic can be prepared by appropriate process parameters.