Cuttlefish-Bone-Structure-like Lamellar Porous Fiber-Based Ceramics with Enhanced Mechanical Performances

Porous fiber-based ceramics have been widely applied in various fields because of their excellent thermal insulation property and high thermal stability property. However, designing porous fibrous ceramics with enhanced comprehensive performances, such as low density, low thermal conductivity, and high mechanical properties at both room temperature and high temperature, is still a challenge and the future development trend. Hence, based on the lightweight cuttlefish bone that possesses a "wall-septa" structure with excellent mechanical performance, we design and fabricate a novel porous fibrous ceramic with the unique fiber-based dual structure of lamellas by the directional freeze-casting method and systematically investigate the effects of lamellar components on the microstructure and mechanical performances of the product. For the desired cuttlefish-bone-structure-like lamellar porous fiber-based ceramics (CLPFCs), the porous framework formed by the overlapping of transversely arranged fibers helps to reduce the density and thermal conductivity of the product, and the longitudinally arranged lamellar structure replaces traditional binders and plays an important role in improving the mechanical properties in the direction parallel to the X-Z plane. Compared with traditional porous fibrous materials reported in the literature, the CLPFCs with an Al₂O₃/SiO₂ molar ratio of 1:2 in the lamellar component exhibits prominent comprehensive performances, such as low density, excellent thermal insulation property, and outstanding mechanical performances at both room temperature and high temperature (3.46 MPa at 1300 °C), indicating that the CLPFCs are a promising candidate for applications in high-temperature thermal insulation systems.