Effect of in situ synthesis of Si2N2O on microstructure and the mechanical properties of fused quartz ceramics

Abstract

Si/SiO2 composite billets were prepared using a low-toxicity gel system, and the resulting billets were sintered at high temperature in nitrogen to synthesize Si2N2O in the central position of the fused silica ceramic matrix. The influences of in situ synthesized Si2N2O on the microstructure and mechanical properties of fused silica ceramics were studied. The results show that Si/SiO2 composite billets can be used to synthesize spike-like and fibrous Si2N2O in situ in nitrogen at 1450 °C. Si2N2O synthesized in situ can improve the mechanical properties and microstructure of quartz ceramics. When the Si/SiO2 composite billet is sintered in nitrogen at 1450 °C for 2 h, the volume density and bending strength of the quartz ceramics can reach 2.36 g/cm3 and 114.37 MPa, respectively.