Study Of Regulating Effect Of Passivation Potential On Corrosion Resistance And Antibacterial Property Of 316L-Cu Stainless Steel

In addition to the traditional advantages of medical 316L stainless steel with excellent corrosion resistance,high strength and good biocompatibility,316L-Cu antibacterial stainless steel also has excellent biological functions such as inhibition of bacterial infection.Thus,it has a great application potential as animplant material.However,for the medical stainless steel used for implant,the artificial passivation is usually employed to improve the corrosion resistance,especially the pitting resistance,which can weaken the release ability of copper ions from the metal surface to a certain extent,and then affect the antibacterial performance.Therefore,this study focused on the balance relationship between the corrosion resistance and the antibacterial property of 316L-Cu stainless steel by adjusting the passivation potential.This will provide direct experimental data for the practical application of antibacterial stainless steel in clinic,hence have scientific significance and application value.In this work,the corrosion resistances of 316L-Cu stainless steel?SS?after passivation at different potentials were studied by potentiodynamic polarization and electrochemical impedance spectroscopy?EIS?.The antibacterial property of passivated 316L-Cu SS was also investigated by plate counting and live/dead cell staining combined with scanning electron microscope?SEM?observation.X-ray photoelectron spectroscope?XPS?was performed to analyze the composition of passive film.The results showed that the corrosion resistance was increased with increase of the passivation potential from 600 mV to 750 mV,due to the enhancement of Cr₂O₃ and Cu?OH?₂ contents in passive film.When the passivation potential was increased to 900 mV,Cr?OH?₃ in passive film gradually dissolved and transformed to CrO₄^2-,decreasing the stability of passive film.The higher compactness of passive film indicated a declined antibacterial performance.It was found that when the passivation potential of 316L-Cu SS was between 580 mV and600 mV,the steel had a better combination of corrosion resistance and antibacterial performance.