Effect of multi-layer graphene on microstructure and mechanical properties of titanium-based composites

Abstract

To achieve the enhanced mechanical properties of the titanium grade 5 (Ti64) alloy, multi-layer graphene (MLG) reinforced Ti64 nanocomposites were successfully fabricated by using spark plasma sintering process. Spherical Ti64 particles with an average diameter of 25 μm, MLG with an average diameter of 5 μm, and an average thickness of 2.5 nm were used in the present study. Microstructure study reveals the in-suit reaction between Ti (matrix) and C (reinforcement) that leads to the formation of TiC along the interface. Further, it was observed that a maximum grain refinement of 32.56% occurs in the Ti64/1.2 wt% MLG nanocomposite. Strengthening along the Ti64 and MLG interface and grain refinement are the primary reasons for the enhanced mechanical properties of the nanocomposites. Nanocomposites with 1.2 wt% MLG exhibit nanohardness of 5.29 GPa, elastic modulus of 119.8 GPa which is 68.4% and 140.5% higher compared with that of Ti64 sintered alloy. The results showed that MLG reinforcement plays an important role in improving the mechanical properties of Ti64 nanocomposites.