Study on Optimum Process Optimization and Corrosion Resistance of Ceramic Layer Prepared by Micro-Arc Oxidation on Surface of Aluminum Alloy

Abstract

Taking 7A52 aluminum alloy as the object, the preparation process optimization and corrosion resistance research of micro-arc oxidation ceramic layer were carried out.The response surface method was used to design the micro-arc oxidation test, and the effects of voltage, frequency, and graphene additive concentration on the thickness and porosity of the micro-arc oxidation ceramic layer were studied in the silicate electrolyte system.Furthermore, the Quadratic model was used to fit the data, the Criteria was used to conduct predictive analysis and perform experimental validation of predictive parameters and response values.The response surface analysis showed that when the conditions were 465.52 V of predicted voltage, 102.66 Hz of frequency and 0.38 g/L of graphene concentration, it possessed 9.992 61% of the optimal porosity and 15.427 7 μm of the optimal ceramic layer thickness.Experiments with the above conditions showed that the measured porosity of as-prepared layer was 9.6%, and the thickness was 12.76 μm.Moreover, the electrochemical tests on the micro-arc oxidation ceramic layer prepared under this conditions indicated that the corrosion potential increased significantly, and the corrosion current decreased, which inferred that the layer had good corrosion resistance.

Keywords

• aluminum alloy|response surface method|micro-arc oxidation|process optimization|corrosion resistance