Thermal shock behavior of the multiple crack system based on Al2TiO5 flexible ceramics

The thermal shock behaviors of the multiple crack system based on aluminum titanate (Al 2 TiO 5 , AT) flexible ceramics are investigated. Two (fine/coarse-grained) systems are employed in this study to observe the influence of the grain size and microcrack size on the thermal shock behaviors of AT flexible ceramics. The findings reveal that these two systems exhibit markedly different adversarial strategies against high-temperature thermal shock. The coarse-grained system disperses the thermal stress by introducing new cracks and making stress evenly dispersed, while the fine-grained one can only concentrate thermal stress on limited microcracks. This is because almost all the grain boundaries in the coarse-grained system could serve as crack source sites, while that was only approximately 1/3 in the fine-grained one. Consequently, as the thermal shock temperature increases, the strain of the coarse-grained system first increases and then decreases, while its strength shows double peaks and double valleys. As for the fine-grained one, the strain decreases with the temperature increase, while its strength first increases and then decreases. Therefore, it can be concluded that the mechanical properties of AT flexible ceramics are closely related to microcracks' size and stress state. And, the conclusion that there exists a favorable state of internal stress and a favorable influence of microcracks that is beneficial to the mechanical performance of AT flexible ceramics could be drawn.