Corrosion Behavior Investigation Of Sintered Nanosilver Under Chlorine Containing Condition

The corrosion resistance of sintered nanosilver film in chloride-containing solution was investigated in this paper.We explored the role of porosity and necking on the corrosion resistance of the sintered nanosilver film by immersion test and electrochemical measurement.Moreover,effect of pH on corrosion behavior of the sintered nanosilver films in chloride-containing solution was also investigated.We selected corrosion resistance as a criterion to optimize sintered parameters.It was found that the corrosion resistance was related to porosity and densification process.Corrosion resistance increased with the increasing heating rate,because porosity was lower in case of the higher heating rate process.For the same reason,corrosion resistance increased with the increasing sintered temperature.The longer sintered time at high temperature,the larger silver grains are,the lower porosity is,the higher corrosion resistance is.Field Emission Scanning Electron Microscope(FE-SEM),Atomic Force Microscope(AFM),Electrochemical Impedance Spectroscopy(EIS),and Inductively Coupled Plasma emission spectrometer(ICP)were used to investigate the effect of pH on corrosion behavior of sintered nanosilver film in chloride-containing solution.Results showed pit corrosion occurred in case of the alkaline chloride-containing solution.OH-adsorption leading oxygen evolution reaction inhibited silver dissolution.The silver tends to dissolve into silver ions in neutral solution without generated corrosion products.Massive corrosion products could be generated in acid solution,but no passivation phenomenon was found.We used EIS to investigate the corrosion mechanism of sintered nanosilver in chloride-containing solution with different pH.EIS results showed an equivalent circuit of electrode with porous structure.Internal sintered nanosilver could suffer from erosion firstly in acid chloride-containing solution because of the existence of H+.Thus,corrosion products generated on the surface was not dense enough so that passivation could not occur in acid chloride-containing solution.