Influence alloying elements of Al and Y in Mgsingle bondLi alloy on the corrosion behavior and wear resistance of microarc oxidation coatings

Microarc oxidation (MAO) coatings were performed on different Mgsingle bondLi alloys (Mgsingle bond14Li, Mg-14Li-3Al, Mg-14Li-3Al-1Y) in silicate electrolyte. The morphology, thickness, corrosion behavior and wear resistance of the coatings were characterized and analyzed. Results indicate that, compared to Mgsingle bond14Li alloy, adding Al and Y in the substrate refines the grains and forms the AlLi and Al2Y phases, contributing to the differences in corrosion behaviors of the Mgsingle bondLi alloys. The alloying elements and uniformly fine microstructure modify the MAO growth process and promote the formation of thick coatings with fewer defects. The MAO coating on the Mg-14Li-3Al-1Y alloy possesses the best corrosion resistance with the icorr of 7.485 × 10−6 A/cm2, due to the densest coating and the thickest inner layer. The reduced porosity and smoother surface enhance the hardness and wear resistance of the MAO coatings on the Mg-14Li-3Al and Mg-14Li-3Al-1Y alloys. It is worth considering the refinement of microstructure and incorporation of passive elements for preparing compact MAO coatings with excellent performances on Mgsingle bondLi alloys.