Determination of structural, mechanical and corrosion properties of titanium alloy surface covered by hybrid system based on graphene monolayer and silicon nitride thin films

Abstract

We report the comparative studies on structural, mechanical and corrosion properties of SiN, SiN/graphene and graphene/SiN hybrid systems deposited on titanium alloy surface. The deposited silicon nitride thin film and silicon nitride/graphene coatings systems were crack free and exhibited good adherence to the substrate and the surface morphology was homogeneous. The graphene/silicon nitride coating system demonstrated a tendency to peeling off and had poor adhesion to the graphene monolayer deposited on the titanium alloy surface. Graphene transferred on titanium alloy surface and silicon nitride thin film surface was a single layer without defects. The hardness for silicon nitride thin film and SiN/graphene coatings was the same (22.4 GPa). Graphene coating has no effect on surface hardness but it decreases the electrochemical activity of the system. The best corrosion resistance has the Ti6Al4V sample coated with SiN/graphene coating system. This sample retains the most stable mechanical and structural parameters during corrosion process. The SiN/graphene coating system greatly improves the mechanical and corrosion properties of examined titanium alloy surface.