Nanoarchitected graphene/ceramic composites

The sintering and densification of graphene/ceramic composites pose significant challenges owing to the high melting point of graphene and ceramic phases. Here we address these challenges by using boron, silicon, and graphene as raw materials to prepare graphene/ceramic composites via spark plasma sintering (SPS) at 1600 °C. Boron and silicon significantly reduce the sintering temperature and improve the relative density of the composites. The abundant Y-type carbon structures effectively inhibit the sliding between graphene layers, improving the shear strength of few-layer graphene. Additionally, the strong Si–C and B–C interfacial bonding synergistically reinforce the composites, leading to exceptional mechanical strength, with the flexural strength of 561 MPa, the compressive strength up to 2.17 GPa, and the microscale compressive strength reaching 11.3 GPa (700 nm in diameter). Meanwhile, the composite exhibits impressive fracture toughness of 7.5 MPa·m^1/2. Molecular dynamics simulations indicate that Y-type carbon structures allow for plastic deformation. The graphene/ceramic composites not only demonstrate superior strengths but are also easy to prepare, making them particularly advantageous for wear-resistant components, ballistic armor and aerospace materials.