Ceramic Papermaking: A Facile Route to Fire-Strengthening, Multifunctional Ultralight SiC Fiber Mat

High-temperature thermal insulation properties of ultralight SiC materials make them highly promising for extreme environment applications. In this study, inspired by ancient paper-making, we demonstrate the room-temperature assembly of pre-formed SiC fibers into an ultralight ceramic "paper" using an aqueous CTAB-stabilized slurry. Under the baptism of 1600°C the "paper" does not burn and strengthens itself. Aerodynamic heat triggers surface oxidation, welding fiber crossings into stable junctions and boosting compressive strength from 49 to 206 kPa, while the skeleton retains its shape with only 1.23% mass loss. The resultant ultralight SiC fiber mat (SFM) carries an ultralow thermal conductivity of 42 mW m^-1 K^-1 and a density of 0.13 g cm^-3, yet survives 80% compression, 135° bending and 45° twisting without fracture. Repeated flame impingement, cyclic airflow scouring and ten-cycle ablation leave the back-face temperature below 400°C, evidencing reliable reusability. Because the "ceramic papermaking" route relies solely on gravity sedimentation and pH-triggered structural assembly, meter-scale or intricately patterned parts can be molded in hours, then dried at 80°C, avoiding complex sol-gel chemistry or high-temperature carbothermal synthesis. The same Seebeck-principle network further endows SFM with real-time temperature measurement (±10°C accuracy), integrating insulation and damage tolerance in one fire-strengthened sheet.