Regulating corrosion reactions to enhance the anti-corrosion and self-healing abilities of PEO coating on magnesium.

Herein, a novel smart chemical strategy for regulating the corrosion reaction to reinforce the plasma electrolytic oxidation (PEO) coating on magnesium by amorphous MnOOH is proposed. The MnOOH film could provide PEO coating with both physical shielding and chemical active healing abilities. During corrosion process, MnOOH spontaneously reacts with the corrosion-produced Mg2+ and OH– to form layered double hydroxides, resulting in high improvement of the long-term anti-corrosion of PEO coating. Moreover, the PEO/MnOOH coating presented a certain self-healing ability for scratches, and could be used for repairing corrosion defects on further coated films. [Display omitted] • An amorphous MnOOH film was prepared on PEO coating via a facile immersion treatment. • MnOOH film could react with corrosion produced Mg2+ and OH- to form protective LDH. • MnOOH film could cut-off the vicious cycle in corrosion reactions of PEO coating. • PEO/MnOOH coating had a certain self-healing ability for scratch and coated films. [ABSTRACT FROM AUTHOR]