Functional Nb2O5 film and Nb2O5 + CuO, Nb2O5 + Graphene, Nb2O5 + CuO + Graphene composite films to modify the properties of Ti6Al4V titanium alloy

• The icorr for Nb2O5 + Graphene on the surface of the Ti6Al4V decreased to 0.01 μA/cm2.
• Composite films caused decrease in the electrochemical activity of the Ti alloy surface.
• The composite films modified the surface hardness of titanium alloy from 5.58 GPa to 9.19 GPa.
• A graphene monolayer has no effect on Nb2O5 thin film hardness.

In this paper comparative studies on the structural, mechanical and corrosion properties of Nb2O5 thin film and Nb2O5 + Graphene, Nb2O5 + CuO and Nb2O5 + CuO + Graphene composite thin films on Ti6Al4V titanium alloy have been investigated. The layers on which the Nb2O5 and Nb2O5 + CuO were deposited by the magnetron sputtering method were crack free and exhibited good adherence to the substrate, and the surface morphology was homogeneous. The graphene transferred on to the Nb2O5 as a single layer without defects. The hardness of the Nb2O5 was approx. 4.78 GPa while the Nb2O5 + CuO had a hardness of 9.19 GPa. The graphene coating had no effect on surface hardness but it decreased the electrochemical activity. The best corrosion resistance was displayed by the Ti6Al4V sample with an Nb2O5 + Graphene thin film.