The preparation of ZrO2-Al2O3 composite ceramic by SLA-3D printing and sintering processing

In this paper, the UV curable ZrO2-Al2O3 composite ceramic pastes based on SLA-3D printing technology were synthetized firstly, and the corresponding ceramic green bodies were 3D printed, and finally the ZrO2-Al2O3 composite ceramic parts were manufactured by a subsequent debinding and sintering process. Our work focuses on the investigation of the microstructure, hardness and fracture toughness of the printed ZrO2-Al2O3 composite ceramics sintered at different maximum sintering temperature and holding time. In case of the sintering temperature of 1500 degrees C and holding time of 60 min, the actual density, hardness and fracture toughness of the ceramics can reach 3.75 g/cm(3), 14.1 GPa and 4.05 MPa.m(1/2), respectively. If the sintering temperature is higher than 1500 degrees C, the abnormal grain growth can occur, resulting in some more reductions in the mechanical properties of ceramics; while when the sintering temperature is lower than 1500 degrees C, the lower driving force makes the grains not fully developed, resulting in a low density of ceramics and worse mechanical properties. With the increase of holding time, the sintering driving force is promoted, making for the grain growth. However, when holding time is more than 60 min, the actual density of ceramics almost remains unchanged, and the mechanical properties of ceramics are not able to be improved further.