Study On Ni-GO Composite Coating For Corrosion Resistance Of Fluoride Ion

The inner surface treatment of the HF standard gas package affects the purity of the product,which directly affects the quality,integration,specific technical indicators and yield of optoelectronics and the accuracy of the device.In this study,the Q235alloy was used as the substrate,and the nickel-based-graphene oxide composite coating was prepared by electro-brush plating technology.By changing the process and parameters of electro-brush plating,a composite coating with uniform distribution of the second phase particles was obtained.Then,the corrosion resistance of nickel-graphene oxide composite coating to fluoride ions was studied,Scanning electron microscope（SEM）,Raman spectrometer,X-ray diffractometer（XRD）were used to characterize the structure and surface morphologies of raw material（graphene oxide）and composite coatings.Electrochemical analysis and immersion tests were used to study the corrosion resistance of composite coatings with different graphene oxide additions in F^-solutions,then the changes in the concentration of elements during the corrosion process were studied by X-ray photoelectron spectroscopy（XPS）to obtain the mechanism of corrosion process.In addition,the influence of bath p H,surfactant types on corrosion resistance of composite coatings were also explored.The results showed that graphene oxide（GO）were co-deposited with nickel atoms on the surface of the substrate,and the GO provided more nucleation sites for nickel atoms,which increased the density of the composite coating and reduced surface defects such as cracks and pores.And the thickness of the plating layer is significantly thicker than that of pure nickel plating.The electrochemical tests showed that when the GO addition amount was 0.75g/L,the corrosion resistance of the composite coating to the F^-was the best.Compared with pure nickel coating,the corrosion current density of Ni-GO/0.75 coating has decreased by 74%,the self-corrosion potential is-0.525V,the positive shift is 0.086V,the charge transfer resistance has increased by 3.16 times,and the corrosion rate has decreased by 68%.After immersed in 0.01M NH₄HF₂ for240 hours,the corrosion weight loss is 3.2mg/cm^-2,which is only 22.2%of that of the pure nickel coating.In addition,the p H of the brush plating bath and the type of surfactant also have a significant impact on the corrosion resistance of the composite coating.It has been verified that the best p H range of the bath was 3.0～3.3.The composite coating obtained by adding anionic surfactants（Sodium dodecyl sulfate）has the best corrosion resistance.Carbon nanotubes are used instead of graphene oxide to prepare nickel-carbon nanotube composite coatings.In order to compare the effect of second phase particles added in solutions.The electrochemical test results show that compared to the pure nickel coating,the corrosion resistance of nickel-carbon nanotube composite coating has been significantly improved,and there is an optimal addition amount（1.0g/L）to achieve the best corrosion resistance,but it is slightly worse than the Ni-GO composite coating.