Conversion coating on magnesium alloy sheet (AZ31) by vanillic acid treatment: Preparation, characterization and corrosion behavior

Herein we report the development and characterization of an eco-friendly protective layer of magnesium vanillate on the surface of a magnesium AZ31 alloy sheet, based on a treatment with 1.0 mmol L−1 vanillic acid aqueous solution. The coating composition was investigated by XPS and FTIR, and the corrosion behavior of the treated sheets was verified by potentiodynamic polarization and EIS. The results obtained show that the treatment improves corrosion protection and the adhesion of polymer coatings, being a promising treatment for corrosion protection of magnesium alloys.