Study On Co-deposition Of Fe-Cr Alloy With Choline Chloride And Glycol Ionic Liquid

The protective and decorative coating will form a chromium-passivation film on the surface of the industry and its daily life,which will prevent the corrosion medium from immersion.Therefore,the Fe-Cr alloy coating has excellent corrosion resistance and beautiful appearance.Widely used in protective-decorative coatings.Traditional Fe-Cr alloy electroplating is mainly carried out in aqueous solution inorganic salt system.The process is co mplex,the treatment of waste electroplating solution is difficult and the cost is high.To solve these problems,ionic liquids as a new electrolyte,electrodeposition of a variety of metals and their alloys,but ionic liquids as electrolyte co-deposition of Fe-Cr alloys are rarely reported at home and abroad.In this paper,dense and bright Fe-Cr deposits were obtained by electrodeposition of ionic liquids prepared from choline chloride chlorion,ethylene glycol chloridiene CrCl₃·6H₂O and FeCl₂·4H₂O on brass cathode using chromium plate as anode,cyclic voltammetry,cathodic polarization,and electrodeposition.The electrochemical mechanism of electrodeposition of Fe-Cr alloy in ChCl-3EG-FeCl₂·4H₂O-CrCl₃·6H₂O ionic liquid was systematically studied by means of chronoamperometric method.The morphology and electrodeposition parameters of Fe-Cr alloy were determined.By electrochemical test in ChCl-3EG-FeCl₂·4H₂O-CrCl₃·6H₂O ionic liquid,it was found that due to the formation of Fe,Cr?II?was reduced to form Cr⁰,which resulted in the co-deposition of Fe-Cr alloy.When the glassy carbon electrode is used as the working electrode,the nucleation of the Fe?Cr?Fe-Cr alloy belongs to the three-position instantaneous nucleation under the control of diffusion.The effect of electrolytic parameters such as cell voltage and temperature on the composition and morphology of Fe-Cr alloy was studied.When the temperature is60?and the cell voltage is 2.7V,the concentration of FeCl₂·4H₂O is 0.3mol/L,the concentration of CrCl₃·6H₂O is 0.3mol/L,the morphology of the Fe-Cr alloy coating is the most compact,which is weedy,and the coating is Fe-Cr alloy.The corrosion resistance of Fe-Cr alloy shows that the content of Cr has a significant effect on the corrosion resistance of Fe-Cr alloy,and the corrosion resistance of Fe-Cr alloy coating decreases with the decrease of Cr content.When Cr content is 18.76 wt%,the corrosion resistance of Fe-Cr alloy coating is the best.