Thermal Shock Resistance of Fiber Dispersed ZrO2 Ceramics

Influence of Y2O3 content on the thermal shock resistance of ZrO2-Y2O3 ceramics including 12vol% of ZrO2-Y2O3 fiber was investigated by varying the content of Y2O3 from 1.5 to 8.0mol%. After specimens were sintered at 1300, 1400 and 1500°C for 2h, bending strength, fracture toughness, thermal conductivity, and thermal expansion coefficient were measured. Thermal shock resistance was characterized by strength degradation before/after thermal shock experiment (quenching temperature difference; ΔT=600K), and it was increased as the Y2O3 content was decreased. It is considered that this is due to the decrease in thermal expansion coefficient caused by the increase in monoclinic phase in the matrix, and the increasing of fracture toughness.