||Magnesium alloys are lightest in structural alloys, which have many excellent
properties, such as high thermal conductivity, good electromagnetic shielding
characteristics, high damping characteristics and good machinability. However,
magnesium exhibits high chemical activity, leading to easily corrosion limited its application. There are many methods proposed to solve this problem. Micro-arc
oxidation (MAO) is a kind of surface treatment, growing a ceramic oxide coating on light metals, such as Mg, Al, and Ti, in short time. The MAO coating consists
condensed and porous layer. The porous layer is often vulnerable to corrosion attack due to some defects. To avert this problem and further enhance the corrosion resistance, anodic arcylic electrophoretic paint coating is employed on AZ61 MAO substrate by electrophoretic deposition. The fractional factorial design and path of steepest ascent study are used to optimize the electrophoretic deposition parameter. Coating was characterized by polarization curves, SEM and salt spray treatment. According to the result, factors influence the thickness of anodic arcylic electrophoretic paint coating are solid content, voltage, MAO treatment time and AIBN concentration in resin.