Rapid synthesis and additive manufacturing of Y₃Si₂C₂ ceramics: Ultrafast high-temperature sintering combined with direct ink writing

Y₃Si₂C₂ powders were successfully fabricated through the in situ reaction of Y and SiC using ultrafast high-temperature sintering (UHS), which is the first attempt to synthesize rare-earth silicates (RE₃Si₂C₂) at an ultrahigh rate. Phase analysis reveals that a relatively pure Y₃Si₂C₂ product is obtained at 1050 °C, exhibiting distinctive lamellar morphology. The synthesized Y₃Si₂C₂ powder was then employed to formulate a shear-thinning ink, and an optimized emulsion-based ink combined with direct ink writing enabled the precise fabrication of honeycomb structures, which exhibited exceptional mechanical properties after sintering. Compared with conventional sintering processes featuring low heating rates (∼10 °C/min) and prolonged dwell times (∼2 h), UHS can efficiently synthesize Y₃Si₂C₂ within significantly shorter times (∼50 s) and at lower temperatures (∼950 °C). The proposed integration of the preparation and forming methods paves the way for the exploration of novel perspectives in the application of Y₃Si₂C₂ in complex-structure ceramics.