Microstructure and toughening mechanism of ZrO2 ceramic

In order to reduce its costs and increase its strength and toughness, 3Y-ZrO2/Al2O3 nanocomposite ceramics is fabricated through pressureless sintering process. Microstructure is detected by SEM and composition is analyzed by EDS. The results show that some of ZrO2 combined with Al2O3 forms ZrO2+Al2O3. solid solutions, and the others form particles which are distributed on grain boundaries and matrixes with different shapes. Those ZrO2 particles locating in the boundaries enhance the ceramic's toughness by two modes: fracturing and tearing, and which one to be occur depends on the location relationship between load and boundary interface. The composition transition, i.e. the solid solution consisting of ZrO2+Al2O3 has formed encircling ZrO2 particles, and it has a positive contribution to ceramics toughness through the combination of chemical bond.