In situ growth mechanism and corrosion resistance of layered double hydroxide coating prepared under mild condition

摘要

In-situ growth of layered double hydroxide (LDH) coatings on magnesium alloy through hydrothermal reaction with high-temperature and high-pressure reaction conditions by an autoclave is not conducive to large -scale production and large -size magnesium alloy parts and increases the experimental risk. This presentation reports the results of an investigation of the design and preparation of several different anions-inserted (including hydroxyl OH −, tungstate WO 42−, metavanadate VO 3−, and phosphate PO 43−) MgAl -LDH coatings on magnesium alloy under relatively mild conditions. The optimum coating e xhibited good adhesion and corrosion protection with an exceptionally low corrosion current density and a very high charge transfer resistance comparable to a hydrothermal method. The in -situ growth of LDH coating in an aqueous solution under atmospheric c onditions and the corrosion protection mechanism of the modified LDH coating will also be discussed. These findings demonstrate the possibility of achieving strongly adhesive and highly corrosion - resistant LDH coatings under atmospheric pressure throughout the preparation process, significantly promoting the industrial application of LDH-based smart coatings for corrosion protection of light alloys.