Study On Corrosion Resistance Of Sol-gel/MAO Composite Films Prepared On Ti6Al4V Alloy

As a light alloy,Ti6Al4V(TC4)alloy is an ideal structural material for aerospace engineering,automotive technology,biomedicine and other fields due to its high strength,low density,good corrosion resistance,and excellent performance.However,due to its inherent phase structure,the surface friction performance is poor.After friction occurs,the self-oxidation film is destroyed,resulting in a decline in corrosion performance,that is,poor tribocorrosion performance,and the decline in tribocorrosion performance has become the main obstacle limiting the widespread application of titanium alloys.The surface of the titanium alloy needs to be treated.Micro-arc oxidation(MAO)technology is a new type of surface treatment technology,which is to immerse the metal in the electrolyte and apply a high voltage to cause micro-arc discharge on the metal surface.A ceramic layer is formed on the surface.According to the nature of spark discharge,micropores and microcracks will be formed on the surface of the ceramic layer during the formation process.Therefore,in the actual working environment,it is necessary to post-process it in order to further improve the protective effect of the ceramic layer.In this paper,a composite film(GO@Sol-gel/MAO)was prepared on the surface of titanium alloy of micro-arc oxidation ceramic layer by sol-gel technology with different concentrations of graphene oxide(GO).Its electrochemical corrosion performance and tribocorrosion performance were studied,and analyzed the protective mechanism of the composite membrane.This paper uses scanning electron microscope(SEM)to characterize the surface morphology of Sol-gel/MAO samples,and uses Raman spectroscopy(Raman)to verify the hybridization conditions of carbon in the gel film layer,and studies by infrared spectroscopy(FT-IR)The chemical bond of the sol was analyzed by X-ray photoelectron spectroscopy(XPS).The results showed that the sol-gel film was successfully attached to the surface of the MAO sample,and the GO and the sol were identified by Raman through infrared spectrum and XPS Identify that the surface of the composite membrane layer contains a layered GO sheet and the I_D/I_Gchanges.In this paper,an electrochemical workstation was used to perform electrochemical analysis(mainly from electrochemical impedance spectroscopy(EIS)and polarization curve)of the composite film in a3.5wt%sodium chloride solution.The results showed that the layered oxidation was attached to the surface of the composite film Graphene(GO)sheets produce good barrier properties,thereby improving the static corrosion performance of the composite film.In this paper,the tribocorrosion analysis of the composite film in3.5wt%sodium chloride solution was carried out using a tribocorrosion workstation.The results show that the GO barrier layer in the composite film reduces the wear during the tribocorrosion process to prevent the corrosion process from occurring.The tribocorrosion performance of the composite film layer is improved.Through the performance analysis of the above composite film,the optimal concentration of GO in the preparation of sol-gel is 100 mL/L.