An irreversible dipping sealing technique for anodized ZE41 Mg alloy

Anodized coatings are porous and sealing has been considered to be an essential step for anodized magnesium alloys. In this study, a new sealing technique was proposed and validated. Anodized ZE41 was dipped in an E-coating bath solution for a few seconds. After baking, the specimen was found to have considerably improved corrosion resistance. The corrosion rate and polarization current densities were found to be more than 3 orders of magnitude lower and the film breakdown potential over 50 mV higher for the anodized ZE41 after sealing in the E-coating bath solution than for the as-anodized ZE41. An irreversible electroless E-coating deposition model and corrosion mitigation mechanism for a sealed specimen are proposed.