Discharge mechanism of ultrasound micro-arc oxidation on magnesium alloy

Magnesium alloy was treated by micro-arc oxidation with ultrasound and the discharge phenomenon was studied.The effect of ultrasound on the discharge life and the number of discharge charges was studied using high speed photography technique.The results indicate that 60 W power ultrasound increases discharge life of single charge and the total number of discharge charges in one discharge period.The size of micro-pore increases and the number of cracks in coating significantly reduce.The dendritic area with a width of 15 μm in magnesium alloy forms during micro-arc oxidation process.Ultrasound eliminates the dendritic structures of micro-arc oxidation magnesium alloy.