Carbonation of Mg powder to enhance the corrosion resistance of Mg-rich primers

This paper is a continuation of our investigation into the characteristic dichotomy of Mg-rich primers between accelerated salt-fog testing and natural weathering. Our earlier study suggested that magnesium powder reacted with atmospheric CO2 to form a protective carbonate layer on its surface. In this study, magnesium powder was treated with aqueous carbonic acid to accelerate magnesium carbonate development. The treated magnesium powder was formulated into a Mg-rich primer and evaluated for its corrosion resistance. The Mg-rich primer formulated with the treated Mg powder performed better in the salt-fog test than the control primer based on untreated Mg powder.

Research highlights
► In Mg-rich primers, Mg is known to react with atmospheric CO2.
► Mg powder was treated with carbonic acid to form a layer of protective MgCO3 on Mg.
► Carbonic acid treated Mg powder improves the performance of Mg-rich primer.