The Corrosion Inhibition Of Rare Passivation And The Corrosion Behavior Of7075Aluminum Alloy In Alkaline Solution With NaCl

For widening7075aluminum alloy material application of alkaline conditions and promotethe development of Rare passivation technology corrosion inhibition on aluminum alloy, thispaper chooses7075aluminum alloy as the research object, uses the alkaline solution as thecorrosive media, and uses copper drip experiment, corrosive media immersion test, open points,Tafel polarization curves, EIS experiments, SEM scanning electron microscopy experiments,XRD diffraction experiments, and corrosion weight loss experiments. Do the research on thecorrosion behavior of7075aluminum alloy in alkaline sodium chloride corrosive media and rarepassivation process for corrosion inhibition of7075aluminum alloy, testing the inhibitionperformance of7075aluminum alloy in Rare passivation corrosion treatment. The thesis isdivided into three processes, the specific processes are as follows:1. In the third chapter of the paper, the experiment uses electrochemical methods to do theresearch on the corrosion behavior of7075aluminum alloy in alkaline NaCl solution in threeaspects, the NaOH concentration, Cl-content and temperature. To analysis7075aluminum alloysurface state by the open electrode potential，and to descript the corrosion behavior bypolarization curve fitting analysis and corrosion analysis of weightlessness. the corrosionbehavior of7075aluminum alloy by the NaOH concentration and temperature impact greater，7075aluminum alloy in which the pH of corrosion medium less than12.4.2. In the fourth and fifth chapter of the paper, the author chooses alkaline NaCl solution asthe corrosive media, selects the rare earth elements cerium nitrate solution as passivationsolution, and uses the chemical immersion method to passivate the7075aluminum alloy. Inorder to obtain the best performance of the passive film corrosion under alkaline conditions, thispaper uses copper sulfate drip experiment, corrosive media immersion test, univariate analysis inthree point of Ce(NO3)3concentration, passivation time and drying time.3. In the sixth chapter of the paper, the author uses the electrochemical method, andcorrosion weight loss experiments to test the inhibition of the a7075luminum alloy afterpassivation treatment in containing0.01mol/L Cl-alkaline corrosive media. The research findsthat the7075aluminum alloy after rare passivation surface passivation film is more than95%CeO2elementa. The corrosion current density is significantly low from1.235862mA cm-2to2.4131×10-2mA cm-2and1.4634×10-4mA cm-2. The corrosion potential is from-1.5926V upto-1.5215V and-1.5075V. The electrochemical impedance is from1.621×103·cm2up to1.528×104·cm2and7.747×106·cm2, and inhibition performance has improved significantly.