Effect of ultraviolet absorbers in high solid loading ceramic pastes on properties of stereolithography 3D printed silica-based ceramic cores

Stereolithography 3D printing technology achieves high-precision fabrication of ceramic cores with complex structures by selectively curing a paste composed of photosensitive resin and ceramic powder using ultraviolet laser. However， the ceramic paste experiences light scattering during curing， leading to an expansion of the cured area， which adversely affects printing accuracy and part performance. Based on a high-solid-loading， thixotropic silica ceramic paste system， the mechanism of ultraviolet absorbers in the preparation of light-curing 3D-printed ceramic core samples and its effect on the properties of the ceramic cores are systematically investigated. By experimentally optimizing the type and amount of ultraviolet absorber， its effects on the printing accuracy， microstructure， sintering shrinkage， and mechanical properties of the ceramic core samples are explored. The results show that an appropriate amount of ultraviolet absorber regulates the spatial distribution of light， effectively reduces scattering of light， and thereby improves the printability of the paste while enhancing interlayer bonding， microstructural uniformity， and mechanical properties. However， there exists an optimal threshold for the amount of ultraviolet absorber. Excessive addition leads to excessive attenuation of light intensity， prolongs the single-layer exposure time， and reduces printing efficiency. Through systematic experimental optimization， 0.25% （mass fraction） TINUVIN B75 is determined as the optimal type and concentration of absorber， achieving the best balance between printing accuracy and efficiency.