Electrodeposited chromate-free organic passive film on the rolled copper foil

The chromium-free passivation system has drawn great focus in view of its advantages of green environmental feature and high performances. In this study, a phytic acid system passivation solution was developed and used to electrodeposit phytic acid film on the surface of rolled copper foil. The micromorphology, surface tension, oxidation and corrosion resistance performance of the phytic acid film were characterized by scanning electron microscope (SEM), dyne pens, X-ray photoelectron spectroscope (XPS) and electrochemical workstation, respectively. The results indicate that the electrodepositing process parameters within a certain range can facilitate the integrated, dense and smooth phytic acid film. Further, the formula of the phytic acid system passivation solution has a significant influence on surface tension, oxidation and corrosion resistance of phytic acid film. With the phytic acid concentration of 8 ml/l, polyethylene glycol concentration of 1 g/l, the cathodic polarization ability is enhanced, which results in the grain refinement, surface oxidability reduction and inhibition efficiency improvement. The three corrosion inhibitors in the aqueous solution could take a unique orientation, form a certain structure, and change the interface state of the system. The comprehensive performance meets the requirements standard of GB/T 36146-2018. Moreover, the environmentally friendly phytic acid passivation system can save more water resources, which is great significance to the green and rapid development of the electronic information industry.