Dielectric and mechanical properties of porous Si3N4 ceramics prepared via low temperature sintering

Borophosphosilicate bonded porous silicon nitride (Si3N4) ceramics were fabricated in air using a conventional ceramic process. The porous Si3N4 ceramics sintered at 1000–1200 °C shows a relatively high flexural strength and good dielectric properties. The influence of the sintering temperature and contents of additives on the flexural strength and dielectric properties of porous Si3N4 ceramics were investigated. Porous Si3N4 ceramics with a porosity of 30–55%, flexural strength of 40–130 MPa, as well as low dielectric constant of 3.5–4.6 were obtained.