Improved Fracture Strength of 5YSZ/Al2O3 Composite Matrix by Addition of SiO2 for Planar Automotive Oxygen Sensor

As the ceramic substrate materials in automobile oxygen sensor, 5YSZ/Al2O3 matrix composite ceramic with different amount of silica are prepared by ball-milling,tape casting and sintering.They are investigated for their microstructure and mechanical properties.The microstructure of the sample is analyzed by Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDX).Fracture strength is measured by ring-on-ring method. It is found that adding 1 wt.% SiO2 into 5YSZ/Al2O3 matrix can improve the strength of composite ceramics.