Insight into Microstructure Evolution and Corrosion Mechanisms of K2ZrF6/Al2O3-Doped Hot-Dip Aluminum/Micro-Arc Oxidation Coatings

In this study, we investigated the impact of K2ZrF6/Al2O3 composite additives on the microstructure evolution and corrosion behavior of ceramic coatings formed through micro-arc oxidation (MAO) treatment on hot-dip aluminum-coated 316L stainless steel surfaces. Our findings revealed the successful preparation of micro-arc oxidation ceramic coatings, presenting a dual-layer structure consisting of a porous micro-arc oxidation ceramic outer layer and a relatively dense/thick hot-dip aluminum inner layer. The incorporation of K2ZrF6/Al2O3 composite additives induced a self-sealing effect on the ceramic coating surface. Optimal coating performance was achieved with a composite additive concentration of 7.5 g/L, resulting in remarkable improvements not only in thickness, hardness, and surface smoothness but also in corrosion resistance. This research introduces a pioneering investigation of K2ZrF6/Al2O3 composite additives in the context of micro-arc oxidation technology, offering fresh perspectives and methodologies for the development of highly corrosion-resistant materials.

Automated summary

This study investigated the effect of K2ZrF6/Al2O3 composite additives on micro-arc oxidation ceramic coatings and found that the additives can improve the performance and corrosion resistance of the coatings.