Modeling of the Influence of Graphene Agglomeration on the Mechanical Properties of Ceramic Composites with Graphene

A model is proposed that describes the porosity, hardness, and fracture toughness of ceramic composites with agglomerates of graphene sheets. It is assumed in the model that graphene sheets are agglomerated during hot pressing of these composites and pores are formed around the agglomerates. The dependences of the porosity, hardness, and fracture toughness of ceramic composites with graphene on the volume fraction of graphene have been calculated within the model. It is shown that pore formation explains the experimentally observed decrease in the hardness and fracture toughness of the composites when the volume fraction of graphene exceeds the critical value. The results obtained within the model are in agreement with experimental data for Al2O3–WC–TiC composites reinforced with graphene sheets.