Double-anticorrosion ability of in-situ superhydrophobic MgAl-LDH coating with excellent stability of the corrosion resistance on magnesium alloy AZ31

We reported the realization of superhydrophobic layered double hydroxide (LDH) coating with the double-anticorrosion mechanism on magnesium alloys. This coating was prepared via in-situ growth of LDHs on the etched AZ31 alloy and the modification was caused by 1H, 1H, 2H, 2H-perfluorooctyltrimethoxysilane. The water contact angle on the coating was as large as 161°, possessing the two-scale rough structure consisting of microislands and LDH crystal nanosheets. The excellent corrosion resistance properties of the superhydrophobic LDH coating can be attributed to the double-anticorrosion mechanism associated with LDH coating and superhydrophobic structure. In addition to the active protection of LDH coating, the passive protection of superhydrophobic coating can suppress the occurrence of ion-exchange reactions, leading to excellent corrosion resistance stability.