High-Temperature Self-Lubricated and Fracture Properties of Alumina/Molybdenum Fibrous Monolithic Ceramic

High-performance Al₂O₃/Mo laminated composites are potential candidates for space applications because of their excellent self-lubricating and mechanical performance. This study aims at solving the anisotropic of this kind of materials by introducing a bamboo structure. Alumina/molybdenum fibrous monolithic ceramics are fabricated from coated alumina fibers to create fibrous microstructures. Analyses were carried to evaluate the relationship between the structure and properties. Results show that the design of imitated bamboo can significantly improve the mechanical properties and tribological anisotropy of Al₂O₃/Mo laminated composite. The bamboo imitation material shows high fracture toughness (8.3 ± 1.6 MPa m^1/2) and work of fracture (3883 ± 1009 J m⁻²) and exhibits good friction reduction (the friction coefficient of all surfaces can be reduced to 0.30) at 800 °C. The excellent mechanical and tribological properties of the material are attributed to the presence of a hierarchical architecture, significant deformation of molybdenum boundaries, load redistribution, and the formation of a continuous molybdenum oxide lubricating and transferring films at high temperature.