Fabrication and mechanical properties of triply period minimal surface porous alumina ceramics based on Digital Light Processing 3D printing technology

Digital Light Processing (DLP) was used to prepare porous alumina ceramics. By comparing rheological and curing properties of slurries with different solid content, alumina slurries with high solid content were proposed. The green bodies were sintered in an air atmosphere after a nitrogen-air double-step debinding, and the relative density of alumina ceramics prepared by a slurry of 72.5 wt.% solid content reached 96%. In addition, three kinds (Gyroid, Diamond, and F-RD) of triply period minimal surface (TPMS) structural models with different volume fractions were established through implicit functions and simulated in Comsol. The simulation results showed that the Gyroid structure has a higher compression property than the other two structures under the same ceramic volume fraction. The TPMS structural alumina green bodies were sintered after DLP printing. The maximum compressive strength of the Gyroid structure with 60% ceramic volume fraction reached 27.42 MPa.