Thermal shock resistance of γ-Y2Si2O7/Y2O3-Al2O3-SiO2 coating for porous Si3N4 ceramics

A double-layer γ-Y2Si2O7/Y2O3-Al2O3-SiO2 glass coating on porous Si3N4 ceramic was fabricated by melt-infiltration/sintering (MIS) method, and its thermal shock behavior was investigated by rapid quenching thermal shock tests and transient finite element simulation method. Coupling effects of coating microstructure and mechanical properties on the thermal shock behavior were discussed. Results show that thickness of the bonding layer and Young's modulus of the surface layer play a decisive role in thermal stress during the thermal shock process. The coating with lower Young's modulus and thicker bonding layer shows better comprehensive performance.