Interface engineering of graphene nanosheet reinforced ZrB$_2$ composites by tuning surface contacts

The mechanical properties of heterophase interfaces are critically important for the behaviour of graphene-reinforced composites. In this work, the structure, adhesion, cleavage and sliding of heterophase interfaces, formed between a ZrB$_2$ matrix and graphene nanosheets, are systematically investigated by density functional theory, and compared to available experimental data. We demonstrate that the surface chemistry of the ZrB$_2$ matrix material largely shapes the interface structures (of either Zr-C-Zr or B-C-B type) and the nature of the interfacial interaction. The Zr-C-Zr interfaces present strong chemical bonding and their response to mechanical stress is significantly influenced by graphene corrugation. In contrast B-C-B interfaces, interacting through the relatively weak $\pi$-$\pi$ stacking, show attributes similar to 2D materials heterostructures. Our theoretical results provide insights into the interface bonding mechanisms in graphene/ceramic composites, and emphasize the prospect for their design via interface engineering enabled by surface contacts.