Corrosion resistance of a self-healing rose-like MgAl-LDH coating intercalated with aspartic acid on AZ31 Mg alloy

[Display omitted] •Aspartate anion-intercalated LDH were fabricated via a one-step hydrothermal method.•The rose flaky MgAl-ASP-LDH nanostructure was obtained.•MgAl-ASP-LDH coating possess excellent corrosion resistance and self-healing function. Intercalating corrosion inhibitor into protective coating with lamellar structure is an effective approach to get high corrosion resistance or a self-healing protection for metallic substrates. In present work, aspartic acid (ASP), an environmental friendly corrosion inhibitor was explored to insert into the MgAl-layered double hydroxides (MgAl-LDHs) on AZ31 magnesium alloys by a simple one-step hydrothermal method. The effect of growth time on the structure, morphology, composition and corrosion resistance of MgAl-ASP-LDHs and the self-healing ability of the scratched MgAl-ASP-LDHs samples were systemically investigated. Owing to the corrosion inhibition of ASP ions and their larger specific surface area to entrap aggressive anionic species such as Cl−, the MgAl-ASP-LDHs were found to have better corrosion resistance than MgAl-NO3−-LDHs. Resulting from the largest ratio of pore coverage and the three-dimensional rose flaky nanostructure, the MgAl-ASP-LDHs hydrothermally grown for 12 h has the best corrosion resistance. Due to the synergistic effect between ASP and laminate structure of LDHs, the MgAl-ASP-LDH coatings exhibit a good self-healing ability.