LAUSR

Abstract Self-healing coatings can inhibit the corrosion of Mg alloys from the damaged areas. In this paper, a duplex self-healing coating, with loading interphase inhibitor into the pores of micro-arc oxidation (MAO) film and doping organic inhibitor into the top paint, is prepared to enhance the self-healing property. The synergistic effect between both inhibitors and the self-healing property of the coating were characterized. The releasing and healing processes were investigated. The results show that 2-mercaptobenzothiazole (MBT) can absorb on the defects of the formed Mg3(PO4)2 and Mg(OH)2 film, which further inhibits the corrosion process by synergistic effect. When the self-healing coating is damaged, phosphate ions can be released from the MAO film quickly while MBT is released from the top paint slowly, then they synergistically inhibit the corrosion of the damaged areas, enhancing the self-healing property greatly in comparison with addition of each inhibitor singly.