Vat photopolymerization-based additive manufacturing of ZrB2-based ultra-high temperature ceramics using low-absorbance precursors

Ultra-high-temperature ceramics (UHTCs) are promising candidates for thermal structures in extreme environments requiring exceptional resistance to temperatures above 2000 °C. Processing these materials via vat photopolymerization-based additive manufacturing remains unattainable, one major obstacle is the high absorbance of conventional ceramic powders. This study introduces an innovative solution utilizing low-absorbance ZrB₂ precursors. The results indicate that carbon sources significantly influence the absorbance of precursors, with sorbitol-derived precursors exhibiting notably lower absorbance values (0.16) at 405 nm compared to pure ZrB₂ powders (0.83). The corresponding photosensitive slurries demonstrate favorable photocuring behavior, facilitating successful additive manufacturing processes. Post-processing through carbonization and boro/carbothermal reduction yields ZrB₂-based ceramics with high mechanical strength and low thermal conductivity, similar to the properties of most porous UHTCs produced by conventional methods. Notably, the printed gyroid-shaped components display mechanical properties comparable to those of conventionally manufactured simple-shaped ones. This approach holds potential for extending the production capabilities to other types of UHTCs.