Preparation Containing ZrO₂Ceramic Layer Through Micro-arc Oxidation On2A12Aluminum Alloy Surface And Study On Corrosion Resistance

The surface corrosion problems of the aluminum alloy, the main reason is to limit itsfurther use.2A12aluminum alloy as the research object, use of micro-arc oxidationtechnology on2A12aluminum alloy surface preparation containing ZrO₂ceramic layer.Research three electrolyte system, the compositional characteristics of the surface layer,determine solution system suitable for the growth of the ZrO₂ceramic coating; and as a basisto discuss the electrolyte system of electrical parameters, formulas and time influence filmcorrosion resistance, structure and growth pattern. The main results show that: film ofzirconium carbonate system main contain MgAl₂O₄, ZrO₂, Zr2O, Al₂O₃phase, ZrO₂phase ismore obvious in film. Further optimization of the parameters found that, the concentration ofzirconium carbonate system and electrical parameters influence corrosion resistance and filmstructure, when the zirconium carbonate concentration reach10g/L, the film is preferably ofcorrosion resistance; in addition, the frequency of600Hz, duty cycle15%, final pressing450V, time10min, the film structure is more dense, showed better corrosion resistance.Analysis show that corrosion resistance is related to film composition and structure, sinceZrO₂has a good corrosion resistance and high temperature stability, the ZrO₂in film willinhibit the diffusion of corrosive media, slow down the corrosion process, in the zirconiumcarbonate system, the appropriate concentration will form a more uniform ZrO₂and Al₂O₃composite film, improve the corrosion resistance of the film from the component design; inaddition, by controlling the electrical parameters will rational design of pore structure,adjustment the channel in the process of corrosion, to achieve a regulation of the filmstructure, to improve the film corrosion resistance according to the need.