Influence of Silicon Nitride (Si3N4) on Mechanical and Dielectric Properties of a Novel Fused Silica Ceramic Composites

Abstract

Porous fused silica (SiO2) ceramic composites were fabricated using a novel gel-casting process and the experiments were conducted using Response Surface Methodology (RSM) central composite with face centred design with a six-centre points approach. The process parameters of a gel-casting process such as solid loading (SL), monomer ratio (RM), monomer content (MC) and additive (Si3N4) were considered as input parameters and flexural strength (FS), porosity (Por.) and dielectric constant (DE) as response parameters. Single parameter and interaction parameter effects on responses were studied. The effectiveness of derived models was compared with Analysis of Variance (ANOVA) at a 95% confidence level. Statistical analysis proved that input parameters have a critical effect on responses. The derived RSM mathematical models have a higher R2 value (FS 97.62%, Por. 95.12% and DE 95.93%) which shows the critical relation between actual and predicted values. The optimal responses obtained were FS 86.173 MPa, Por. 39.767% and DE 6.949 corresponding parameters process parameters SL 47.95%, additive (Si3N4) 10.43 wt%, MC 15 wt% and RM 3.