Fabrication of bioinspired structured alumina composites with enhanced fracture toughness

Strength and toughness have been generally deemed as two incompatible properties in many materials. However, balanced toughness and strength have been observed in biomaterials, whose hard and soft phases are arranged into a unique and hierarchical architecture. Therefore, it is essential to develop processing technologies that can mimic the structures observed in biomaterials. In this work, bioinspired alumina-PMMA composites were achieved via freeze casting. Our experimental results demonstrate the crucial contribution of the interfacial strength to the high toughness (3.1 MPa m1/2) of the bioinspired composites, which is higher than nacre (2.4 MPa m1/2). In addition, with the help of numerical simulation analysis, it is found that the interfacial strength can influence the failure mode of the bioinspired composites