Room-temperature rapid fabrication of porous ZnO ceramics by flash sintering with carbon electrodes

Porous ZnO ceramics with tunable pore structures were prepared in air at room-temperature via flash sintering using the pore-former method in conjunction with a flash sintering device based on a carbon electrode structure. By employing various amounts of basic zinc carbonate as the pore-former, ceramics with adjustable porosity were obtained. The results showed that as the content of basic zinc carbonate increased, both the sample porosity and average pore size increased significantly; at high contents, millimeter-scale macropores and well-developed mesoporous structures were achieved. Flash sintering enabled rapid densification within a very short time, demonstrating high efficiency and energy-saving advantages. Mechanical property tests indicated that increased porosity led to decreases in Vickers hardness and fracture toughness. This study applies the room-temperature flash sintering technology to porous ceramic materials, expanding the application scope of the room-temperature flash sintering technology and providing a more efficient and energy-saving new method for the preparation of porous ceramic materials.