Synergistic strengthening effect of titanium matrix composites reinforced by graphene oxide and carbon nanotubes

Titanium matrix composites reinforced by graphene oxide (GO) and carbon nanotube (CNT) were successfully prepared by hot-pressing sintering. The effect of GO content on dispersion and particle size of CNT was analysed. In addition, the microstructure, phase structure and mechanical properties of Ti/GO-CNT composites were characterized, and the synergistic strengthening mechanism was investigated. The results show that dispersion of CNT can be significantly improved by adding GO. TiC particles with size of 100–200 nm are formed in situ between matrix and reinforcements. CNT and GO still partly keep an integrated structure after sintering. A significant synergetic effect was observed between GO and CNT that improved the mechanical properties of the composite. The maximum hardness and yield strength of the composite were 771.5 HV and 1387.1 MPa, which is 150% and 74% higher than that of pure Ti when the GO/CNT ratio is 5:1. The synergistic strength enhancement reaches a maximum when GO/CNT ratio is 1:1. [Display omitted] •The dispersion of carbon nanotubes can be improved by addition of graphene oxide.•Graphene oxide and carbon nanotubes can be used as ideal reinforcements to strengthen the titanium matrix.•A clean and non-equilibrium interface between titanium and carbonaceous nanomaterials was formed.•Synergistic strengthening effect between carbon nanotubes and graphene oxide was obtained.