Study On Cerium-Based Conversion Caoting Of Aluminum Alloy By Electrochemical Depodition And The Film's Corrosion Resistance

Cerium-based conversion coating was successfully deposited on corrosion-resisting aluminium alloy LF21 in cerium solution using cathodic electrolysis method. The optimum technology was obtained by primary technology and orthogonal experiment. Various experimental methods were adopted to study the corrosion resistance of the film. The results revealed that the quality of the films was obviously improved, and the influential factors of technology had significant effects on the film's corrosion resistance. The performance of the conversion coating on LF21 by different pretreatment technology has been studied by SEM, energy spectroscopy, polarization curve measurement and EIS,and we got a better pretreatment technology from the results. We tested the corrosion resistance of Cerium-based conversion coating by electrochemical way, coating by chemical way and naked specimen in order to confirm the superiority of the electrochemical way, the results approved our estimation.It showed that the surface of the film by cathodic electrolysis method distributed the oxide and hydroxide of cerium homogeneously,...