Accuracy controlling and mechanical behaviors of precursor-derived SiOC ceramic microlattices by projection micro stereolithography (PμSL) 3D printing

Precursor-derived SiOC ceramic (PDC-SiOC) microlattices exhibit excellent oxidation resistance, high-temperature stability, as well as superior mechanical properties. However, the printing accuracy of PDC-SiOC microlattices by 3D printing is still limited, and the mechanical properties of 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 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, PDC-SiOC microlattices with different truss diameters in the 52-220 μm range were fabricated and their mechanical properties were investigated. The PDC-SiOC microlattices with 52 μm truss diameter exhibited a higher compression strength (31 MPa) than those with bigger truss diameters. The size effect among 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 size effect in ceramic structures.