Reasearch On The Sealing Methods And The Performance Of Anodic Oxidation Film On Aluminum Alloy

Two passive sealing methods of sulfuric acid-boric acid anodic oxidation filmwas studied in this thesis:①Ce(NO3)3+KMnO4②Ce(NO3)3+KMnO4+H2O2,andthe film performance was analysed by the electrochemical property analysis、solution immersion、salt spray、drip test、the weight loss test in phosphorusacid-chromic acid without nitric acid. The basic formulations of Ce(NO3)3+KMnO4sealing method and Ce(NO3)3+KMnO4+H2O2sealing method wereconfirmed by orthogonal exprimental. Then base of this, the optimum formulationswere confirmed though changing the content of the KMnO4. The generate ofpassivation film that through Ce(NO3)3+KMnO4passive sealing was confirmedthat it is very dense and there is a binding between the oxide film and base alloys.The corrosion resisitant behavior of the unsealed oxide film、fill sealed oxide film(sealing by Ce(NO3)3、sealing at room temperature、boiling water sealing)、passivesealed oxide film were compared and it was founded that the oxide films afterpassive sealing methods or fill sealing methods the corrosion resisitant behavior isbetter than unsealed oxide film. The oxide film after Ce(NO3)3+KMnO4passivesealing have the best corrosion resisitance among the oxide films that after passivesealing methods, but the oxide films that after fill sealing methods have thedifferent situations. The oxide film after boiling water sealing have the bestcorrosion resisitance when it in the acid solution and neutral salt solution,and thefilm after Ce(NO3)3sealing have the best corrosion resisitance when it in the alkalisolution. During the short time corrosion, the oxide film after passive sealingmethods have the better corrosion resisitance than the oxide films that after fillsealing methods, or else, the oxide films that after fill sealing methods the bettercorrosion resisitance than the the oxide film after passive sealing methods.