Effect of cetyltrimethylammonium bromide on corrosion resistance of electroplated copper-nickel alloy coating
[Introduction]The effect of the mass concentration of cetyltrimethylammonium bromide(CTAB)on the corrosion resistance of electroplated Cu-Ni alloy coating needs to be studied.[Method]The corrosion resistance of Cu-Ni alloy coating was examined by immersion corrosion test,Tafel curve measurement,and electrochemical impedance spectroscopy(EIS).The surface morphology,elemental composition,and phase structure of Cu-Ni alloy coating were characterized by scanning electron microscopy(SEM),energy-dispersive spectroscopy(EDS),and X-ray diffraction(XRD).The inclusion of CTAB in the coating was analyzed by Fourier-transform infrared spectroscopy(FTIR).The hydrophobicity of Cu-Ni alloy coating was evaluated by contact angle measurement.The effect of CTAB concentration on the electrodeposition behavior of Cu,Ni,and Cu-Ni alloy was also studied by cathodic polarization curve measurement.[Result]The corrosion resistance of Cu-Ni alloy coating was initially improved and then deteriorated with the increasing of CTAB concentration.The Cu-Ni alloy coating electroplated with 80 mg/L of CTAB featured a cauliflower-like spatial three-dimensional morphology,contained 50.25%of Cu and 40.86%of Ni,had a contact angle of 129.49° to corrosive solution,and showed the best corrosion resistance.[Conclusion]The addition of appropriate amount of CTAB to the plating bath can significantly improve the corrosion resistance of Cu-Ni alloy coating.