Investigation on the microcrcaks strengthening effect in the damage behavior of Al2TiO5 flexible ceramics based on the AE

In this study, the effect of microcrcaks strengthening on damage evolution of Al2TiO5 (AT) flexible ceramics was investigated by acoustic emission (AE). Results reveal that with increasing content of ZrO2, the strength of AT flexible ceramics improves gradually and the strain increases at first then decreases. When the content of ZrO2 is 12% and 8%, the strength and strain at maximum stress are increased by 154.92% and 38.27%, respectively. In addition, thanks to the "strengthening effect" of ZrTiO4 on grain boundary microcracks, the damage development thresholds (sigma(min) and sigma(onset)), elastic modulus and fracture toughness of AT flexible ceramics modified with ZrO2 are significantly improved. Moreover, the visible transverse cracks and matrix shedding in ATZ-0 are the most, but the cumulative AE damage events in ATZ-8 and ATZ-4 are more than ATZ-0 at late stage, for which the fracture of ZrTiO4 glass phase and crack branching induced by ZrTiO4 should be responsible.