Abstract: Lightweight high-strength and tough composites have enormous potentials in a multitude of fields including biomaterials, sporting goods, aerospace and automobile industries. Herein, we present a strategy to develop a novel bulk Al/SiC composite with a nacre/foam hybrid structure to combine excellent lightweight of foams with outstanding strength and toughness of nacre. To reduce the adverse effect of foam pores on mechanical properties, we further propose to strengthen the foams with 3D nanofiber networks, obtaining a nacre/nanofiber reinforced foam structure. Simultaneously, new particle-bubble co-assembly and selective infiltration technologies are proposed to prepare the novel nacre/foam and nacre/nanofiber reinforced foam structures. The nacre/nanofiber reinforced foam composite shows greater specific strength and toughness than the nacre/foam composite, conventional dense Al/SiC composites and many engineering materials. Our approach opens a promising new avenue for the structure design and manufacturing of lightweight, high-performance structural materials.

Key words: Nanofiber reinforced foams, Nacre-mimetic, Microstructure, Mechanical properties, Freeze-casting, Metal-ceramic composites