Toughening mechanism and thermal shock resistance of ZrO2 (3Y)/Fe28at-%Al composites evaluated by indentation techniques

Abstract

Toughening mechanism and thermal shock resistance of monoclinic ZrO2 (3Y) and ZrO2 (3Y)/Fe28at-%Al composites were investigated by indentation techniques. ZrO2 (3Y)/Fe28at-%Al composites exhibited more pronounced R curve behaviour than the monolithic ZrO2 (3Y). Quantitative analysis of toughening behaviour indicated that the enhanced toughness was attributed to the synergistic effect between crack bridging toughening and phase transformation toughening. Thermal shock resistance of as prepared composite was evaluated by indentation–quench method. Compared with monoclinic ZrO2 (3Y), ZrO2 (3Y)/Fe28at-%Al composites had higher critical thermal shock temperature difference ΔTU at which cracks grow unstably. The thermal shock resistance parameters R, R′ and R′′′′ were also calculated to evaluate the thermal shock resistance. It was found that the addition of Fe28at-%Al particles could lead to higher KIC, thermal conductivity and lower Yong’s modulus, thus resulting in higher ΔTU values of ZrO2 (3Y)/Fe28at-%Al composites than monoclinc ZrO2 (3Y).