Reinforcement with graphene nanoflakes in titanium matrix composites

Graphene reinforced bulk titanium matrix composites (TMCs) were successfully fabricated via powder metallurgy approach. 0.5 wt% graphene nanoflakes (GNFs) and Ti6Al4V mixture powders were prepared by a wet process. The composites were then consolidated using hot isostatic pressing (HIP) with a pressure of 150 MPa at 700 °C followed by isothermal forging with a forging ratio of 3 at 970 °C. The microstructure and mechanical properties of TMCs had been investigated by optical microscopy, SEM, TEM and static tensile tests. Microstructure observation illustrated a uniform distribution of graphene in the composite and in-situ formed TiC particles at the metallurgical interface between titanium matrix and graphene. Compared with the unreinforced titanium matrix, the 0.5 wt% GNFs reinforced composite exhibits significantly improved strength without losing ductility, which demonstrates that GNFs could actually act as superb reinforcements in TMCs.