Precursor-derived ceramic SiOC (PDC-SiOC) microlattices exhibit excellent oxidation resistance, high-temperature stability, and superior mechanical properties. However, the printing accuracy of the PDC-SiOC microlattices by 3D printing is still limited, and mechanical properties of the PDC-SiOC microlattices have not been studied systematically. Here, PDC-SiOC octet microlattices were fabricated by projection micro stereolithography (PμSL) 3D printing, and photoabsorber (Sudan III)’s effect on the accuracy was systematically analyzed. The results showed that the addition of Sudan III improved the printing accuracy significantly. Then, the ceramization process of the green body was analyzed in detail. The order of the green body decreased, and most of their chemical bonds were broken during pyrolysis. After that, the PDC-SiOC microlattices with different truss diameters in the range of 52–220 μm were fabricated, and their mechanical properties were investigated. The PDC-SiOC microlattices with a truss diameter of 52 μm exhibited higher compression strength (31 MPa) than those with bigger truss diameters. The size effect among the PDC-SiOC microlattices was analyzed. Our work provides a deeper insight into the manufacturing of PDC-SiOC micro-scaled architectures by 3D printing and paves a path to the research of the size effect in ceramic structures.

Cellular ceramic structures (CCSs) are promising candidates for structural components in aerospace and modern industry because of their extraordinary physical and chemical properties. Herein, the CCSs with different structural parameters, i.e., relative density, layer, size of unit cells, and structural configuration, were designed and prepared by digital light processing (DLP)-based additive manufacturing (AM) technology to investigate their responses under compressive loading systematically. It was demonstrated that as the relative density increased and the size of the unit cells decreased, the mechanical properties of one-layer CCSs increased. The mechanical properties of three-layer CCSs were more outstanding than those of the CCSs with one and two layers. In addition, structural configurations also played a vital role in the mechanical properties of the CCSs. Overall, the mechanical properties of the CCSs from superior to inferior were that with the structural configurations of modified body-centered cubic (MBCC), Octet, SchwarzP, IWP, and body-centered cubic (BCC). Furthermore, structural parameters also had significant impacts on the failure mode of the CCSs under compressive loading. As the relative density increased, the failure mode of the one-layer CCSs changed from parallel–vertical–inclined mode to parallel–vertical mode. It was worth noting that the size of the unit cells did not alter the failure mode. Inclined fracture took a greater proportion in the failure mode of the multi-layer CCSs. But it could be suppressed by the increased relative density. Similarly, the proportions of the parallel–vertical mode and the fracture along a specific plane always changed with the variation of the structural configurations. This study will serve as the base for investigating the mechanical properties of the CCSs.