Superior tribological and anti-corrosion performance of corrosion inhibitors intercalated LDH-MAO coating on AZ31 Mg alloys

Sodium dodecyl sulfate (SDS) and 8-Hydroxyquinoline (8-HQ) intercalated layered double hydroxides (LDH) sheets were in-situ formed in MAO layer to prepare a composite coating (CI@LDH-MAO) on AZ31 magnesium alloy. This composite coating demonstrates commendable anti-corrosion performance, primarily attributed to the formation of LDH sheets and insoluble Mg(HQ)2 compounds. The electrochemical impedance modulus of the composite coating surpasses that of the MAO coating by three orders of magnitude after immersion of 360 h. Concurrently, the CI@LDH-MAO composite coating exhibits exemplary tribological properties, characterized by a friction coefficient of approximately 0.19 and a wear rate of (11.5 ± 1.5)× 10−6 mm3/(N·m). This outstanding tribological performance can be ascribed to enhanced interaction of lubricants with the friction interface by 8-HQ and SDS anions.