Graphene nanosheet/titanium carbide composites of a fine-grained structure and improved mechanical properties

Dense graphene nanosheets (GNSs)/titanium carbide (TiC) composites have been produced from graphene oxide (GO)/TiC composite powders by spark plasma sintering. It is unexpected to observe that an introduction of 1.0 vol% GNSs from GO completely stops TiC grain growth by pinning their grain boundaries and densification is completed under the confinement of the flexible GNSs. Such a mechanism assumedly comes from the ultra-thin structure of GNSs, which indicates a crucial role GNSs may play in ceramic processing and has not been reported previously. Compared with monolithic TiC, the flexural strength of GNSs/TiC composites is significantly improved as a result of the refinement of matrix grains and excellent strength of GNSs, while the fracture toughness is enhanced due mainly to crack deflection, GNSs bridging and pull-out.