Guifang Han

Flexible HfO2/SiC composite nanofibrous membranes were fabricated via a polymer-derived ceramic strategy by incorporating HfO2 nanocrystals into a SiC matrix. The optimized membrane exhibits a tensile strength of 1.97 MPa, a static load-bearing capability of approximately 3800 times its own weight, and excellent cyclic bending durability, maintaining ΔR/R0 below 3% after 1.6 × 104 cycles under 180° repeated bending. These results demonstrate its robust mechanical stability under both static loading and repeated bending deformation. Concurrently, the membrane achieves a low thermal conductivity of 0.1513 W·m−1·K−1 and a high infrared emissivity of ∼0.95. When subjected to direct exposure to a 1200 °C flame, a 2.5 mm-thick membrane exhibits a backside temperature of only 172.6 °C. The measured temperature-difference sustainability per unit thickness is 1.19 × 105 °C·s·mm−1 under prolonged thermal exposure, which is 1.6 times that of conventional ceramic, fibrous, and aerogel insulators. Moreover, molecular dynamics simulations provide further evidence that the incorporation of HfO2 has a reinforcing effect. These results highlight the potential of HfO2/SiC nanofibrous membranes for lightweight thermal protection applications under extreme environments.

Alumina‐based ceramics demonstrate remarkable hardness and wear resistance; however, their intrinsic high brittleness and low fracture toughness pose significant challenges in the fabrication of complex components using conventional processing techniques. The emergence of additive manufacturing technology has enabled the fabrication of complex‐structured alumina ceramics. In this study, nano‐silica (SiO ₂ ) was incorporated into zirconia‐toughened alumina (ZTA) ceramic powders for digital light processing (DLP) 3D printing. During subsequent debinding and sintering, the SiO ₂ reacted in situ with alumina to form mullite particles, which contributed to microstructural refinement and toughening. Optimal properties‐Vickers hardness (16.2 GPa), flexural strength (463.8 MPa), and fracture toughness (4.34 MPa·m ^1/2 )‐were achieved at 3 wt% SiO ₂ . The mechanical performance of the printed ceramics was significantly enhanced, demonstrating a novel strategy for producing high‐strength alumina‐based ceramics via DLP 3D printing.