中国科学院材料磨损与防护重点实验室/先进润滑与防护材料研究发展中心知识库

Natural composites have very simple compositions and complex hierarchical architectures consisting of several different levels. These features simultaneously endow them with strength, toughness, functional adaptation and damage-healing characteristics. Inspired by the microstructural features of natural materials, this work successfully fabricated Al₂O₃/reduced graphene oxide (rGO) fibrous monolithic ceramics with bamboo-like structures by introducing a thin graphene oxide around Al₂O₃ fiber cells to form the rGO boundary phase. The detailed evolutions of the crack extension and fracture responses were investigated by a J-integral method, and these bamboo-like composites demonstrated high structural reliability with excellent damage tolerance and progressive plastic failure behavior. With the fiber cell diameter of 0.6 mm, such composites exhibited fracture toughness (29.46±3.04 MPa·m^1/2) and work of fracture (799±127 J×m^-2) that were 475% and 1075% higher than those of the monolithic Al₂O₃ ceramic, respectively. Their excellent fracture-resistant behavior was attributed to the hierarchical architectures that provide crack deflection, delamination and load redistribution. The results also established the structure-activity relationships to guide the design and fabrication of these bamboo-like composites.