Microstructural and Mechanical Properties Characterization of Graphene Oxide-Reinforced Ti-Matrix Composites

The 0.1-0.7 wt.% graphene oxide (GO)-reinforced Ti-matrix composites (TMCs) were prepared by the hot-pressed sintering method. The effects of GO content on the mechanical properties of TMCs were investigated. The microstructure of TMCs was analyzed. The results show that the microstructure of Ti and TMCs is equiaxed alpha. The average grain size of TMCs decreases with GO increasing. GO can react with Ti to form TiC at high temperatures. Meanwhile, GO is also presented in the matrix. The hardness of TMCs is higher than that of pure Ti. The maximum hardness is 320 HV, which is 43% higher than that of pure Ti. The yield strength of Ti-0.5 wt.% GO sintered at 1373 K is 1324 MPa, 77% more than pure Ti. The strengthening mechanism of TMCs is the fine-grained strengthening and the reinforcement that bear the stress from the matrix. The friction coefficient of Ti-0.3 wt.% GO sintered at 1373 K comes up to 0.50, which is reduced by 0.2 compared with pure Ti.