Novel route to β ‐SiAlON–SiO ₂ ceramic composites

This paper reports a novel synthetic route to prepare dense β‐SiAlON–SiO2 ceramic composites. The stoichiometric β‐Si4Al2O2N6 extrudates prepared by the reaction sintering of α‐Si3N4, α‐Al2O3, AlN and Y2O3 precursor mixture at 1675°C for 4 h were fine ground and mixed with different amounts of commercial fused silica (20, 40, 50, 60 and 80 wt‐%) powder, dry pressed and sintered for 3–4 h at 1500–1750°C. These sintered materials were thoroughly characterised for bulk density, apparent porosity, water absorption capacity, phase composition, microstructure, hardness, dielectric constant and coefficient of thermal expansion. These characterisation results are presented and discussed in this paper.