The effect of graphene reinforcement on the mechanical properties of Al2O3 ceramics rapidly sintered by high-frequency induction heating

Despite of many attractive properties, the low fracture toughness of Al2O3 ceramic limits its wide application. One of the most obvious tactics to improve the mechanical properties has been to add a reinforcing agent to formulate a nanostructured composite material. In this respect, graphene was evaluated as the reinforcing agent of Al2O3 ceramics using high-frequency induction heated sintering (HFIHS). Highly dense alumina-graphene composites with a relative density of up to 99.6% were obtained within 2 min by HFIHS under a pressure of 80 MPa. The rapid consolidation method allowed the retainment of the nano-scale microstructure by inhibiting the grain growth. The grain size of alumina was reduced significantly by the addition of graphene. The addition of graphene to Al2O3 simultaneously improved the fracture toughness and hardness of alumina-graphene composite.