<p>Silica ceramic cores are widely used in the manufacturing of hollow blades for aircraft engines due to the excellent mechanical and chemical properties. 3D printed silica ceramics often face the problem of low flexural strength at the application temperature of 1250&#xa0;°C, and the simultaneous requirements for both adequate porosity and strength limit their manufacturing process. This study utilized three different impregnation solutions to analyze the effects of sol types on the microstructure and flexural strength of 3D printed silica ceramics. The results indicate that after impregnation with silica sol (SS), alumina sol (AS), and zirconia sol (ZS), the flexural strength of the 3D printed ceramics all improved effectively. SEM showed that the SiO₂ ceramic cores impregnated with the AS solution did not produce cracks, possessed a more uniform microstructure, a lower surface roughness and exhibited the best overall performance, with an open porosity of 24.21 ± 0.11 vol%, bulk density of 1.71 ± 0.01&#xa0;g/cm³, and a flexural strength of 24.35 ± 0.11&#xa0;MPa.</p> Graphical abstract <p></p>