Mechanical and Dielectric Properties of Al2O3/Graphene Nanocomposite Ceramics

Investigations of the mechanical and conductive properties of Al₂O₃ nanoceramics containing graphene from 0.5 to 2 wt %, processed by the plasma-spark sintering method, are conducted. The optimal content of graphene in Al₂O₃ ceramics is determined. It is shown that the addition of 0.5–1 wt % of graphene contributes to an increase in the nanohardness (by 13%) and fracture toughness (not less than 27%). It is established that the elastic modulus of Al₂O₃ ceramics does not depend on the graphene content, but decreases in a gradient with displacement of the diagnosed area from the center to the periphery. The possibility of a significant decrease in the electrical resistance with an increase in the temperature of the composite and the frequency of the alternating current is demonstrated.