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

Abstract

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, 2Hperfluorooctyltrimethoxysilane. 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.

The preparation and corrosion resistance of superhydrophobic coating on Cu plate via two-step electrodeposition

“…Low surface energy allows the coating to repel water and other liquids, bolstering its protective qualities. According to the reports, various methods can be used to obtain rough structures at the micro-nano scale (Xu et al, 2021), such as etching (Doskoc ˇil et al, 2022;Liu et al, 2023), plating (Kamde et al, 2022;Zhang and Shen, 2023), hydrothermal (Guo et al, 2023;Han et al, 2023;Tang et al, 2023), chemical conversion coating (Wang et al, 2022a(Wang et al, , 2022b(Wang et al, , 2022cWang et al, 2023), chemical oxidation (Song et al, 2022), spray (Zheng et al, 2023). Organic long-chain molecules, as low surface energy agents, are commonly used to construct the modifier layer to reduce surface energy, such as stearic acid (Wang et al, 2022a(Wang et al, , 2022b(Wang et al, , 2022cLi et al, 2023a), myristic acid (Tian et al, 2023), lauric acid (Wang et al, 2020;Zhu et al, 2021), hexadecyltrimethoxysilane (Ma et al, 2023).…”