Effect of Si3N4 nanowires on the mechanical properties and dielectric constant of porous Si3N4 ceramics

Abstract

The high strength and low dielectric constant of silicon nitride (Si3N4) ceramics are an irreconcilable conflict. It is a compromise to introduce a suitable reinforcing phase in Si3N4 ceramics to receive well dielectric properties without excessive loss of mechanical properties. In this paper, Si3N4 nanowires were in-situ synthesized by pyrolysis of polysilazane with Si3N4 nanopowders as catalyst without introduction of impurities in Si3N4 porous ceramics. The formed Si3N4 nanowires not only improve the mechanical property but also reduce dielectric constant of porous Si3N4 ceramic.