Flash-PEO as an alternative to chromate conversion coatings for corrosion protection of Mg alloy

Abstract

In the present work, a flash-PEO coating is developed on AZ31B alloy in a combination of silicate, phosphate, and fluoride based electrolyte in order to offer a green alternative to chromate conversion coatings. Multilevel active protection is achieved through synergetic combination of self-sealing effect of PEO coating itself and active inhibition provided by an organic inhibitor impregnated in PEO pores in a post-treatment step. The results indicate that flash-PEO coatings, loaded with organic corrosion inhibitors, can be recommended for exploitation on industrial level as an equally effective corrosion protection system alternative to CCC for paint-bearing and paint-free applications.