The hybrid graphene multilayer system (graphene/SiN/graphene) coupled with titanium alloy (Ti6Al4V) — structural, mechanical and corrosion characterisation

• Graphene/silicon nitride/graphene system improves titanium alloy surface hardness.
• Corrosion current density for graphene/silicon nitride/graphene system decreases to 0.033 μA/cm2.
• Corrosion potential for graphene/silicon nitride/graphene system shifts to the noble potentials.
• Graphene/silicon nitride/graphene system has a very stable the course of potential.

In this paper the studies on structural, mechanical and corrosion properties of the hybrid graphene multilayer system (graphene/SiN/graphene) coupled with titanium alloy (Ti6Al4V) have been investigated. We have shown that the graphene/SiN/graphene multilayer hybrid system deposited on titanium alloy surfaces, improves surface hardness (23 GPa) and the corrosion properties of the Ti6Al4V alloy in very aggressive environments. Furthermore, this multilayer hybrid system has a very stable course of electrochemical potential in comparison with pure silicon nitride thin film with the same thickness. Unfortunately, this system does not maintain structural and mechanical stability during the corrosion process. The structure of the coating system becomes porous, which is characterised by low hardness (0.62 GPa) and low Young's modulus — 69 GPa.