Process Study On Improving Corrosion Resistance Of 6061 Aluminum Alloy Anodized Film

6061 aluminum alloy is an Al-Mg-Si series aluminum alloy.This series of aluminum alloys has good plasticity and corrosion resistance,is easy to be anodized,and is widely used in architectural decoration,household kitchenware,automobiles and aviation.The anodizing process can improve the performance of aluminum alloy surface brightness,hardness,wear resistance and corrosion resistance,expand the scope of application and extend the service life.Therefore,anodized aluminum alloys are often applied to exterior body parts of passenger cars such as luggage racks,body bright strips and window frame trims.In this paper,based on the experience of the enterprise project,the 6061 aluminum alloy luggage rack is used as a sample to study the anodizing and sealing process to improve the comprehensive corrosion resistance of the product.A single sulfuric acid-based electrolyte was used to anodize the 6061 aluminum alloy by a constant current density method,and the time,temperature and current density of the anodization were determined.On this basis,three kinds of additives(cerium sulfate,citric acid,glycerol)were selected as additives,and the effects of different additive concentrations on the growth of the anodized film and film properties were studied.They are: cerium sulfate: 0.8g / L;citric acid: 8g/L;glycerol: 6g/L.The anodic oxide film was prepared at the optimal concentration of the three additives.Compared with the effects of the three additives on the corrosion resistance of the film,the best additive was determined to be cerium sulfate.Add 0.8 g / L of cerium sulfate to the basic electrolyte to prepare an anodic oxide film,as a sample to study the oxide film sealing process.Introduce the potting process as an intermediate sealing,combined with conventional hot sealing and cold sealing,to perform three-step sealing treatment on the anodized film.Focused on the ceramic sealing process,starting from the sealing mechanism,discussed the influence of the concentration of ceramic agent,temperature and sealing time on the performance of the oxide film,and determined the best process condition of this sealing method: the concentration of ceramic agent 70 g / L,sealing time is 30 min,sealing temperature is 40 ℃.Finally,using the relevant standards in the automotive industry,the samples can be subjected to high temperature resistance test,strong alkali resistance test and neutral salt spray test,which can meet the requirements of the standard at the same time,that is,after anodizing and three-step sealing treatment,aluminum The alloy improves the surface properties of the anodized film.