Magnesium-lithium (Mg-Li) alloys are promising lightweight materials for engineering applications, but their use is limited by poor wear and corrosion resistance. To address those challenges, micro-arc oxidation (MAO) coatings were fabricated on a model Mg-Li alloy LA81 using electrolytes containing conductive ceramic nanoparticles (TiBCN). Results suggest that TiBCN enhances electrolyte conductivity and altering arc discharge behavior, thereby reducing overall porosity of the resultant MAO coatings. Comprehensive characterization including coating thickness, microstructure, triboelectrochemical and corrosion resistance identify 2.5 g/L TiBCN as the optimal concentration. This formulation exhibits enhanced corrosion resistance, wear resistance and a notably low pore density. Three-dimensional evolution of corrosion in the optimized MAO coating was examined using synchrotron X-ray computed tomography. In corrosive environments, the combined effects of corrosion and expansion of corrosion products alter size, shape, and number of microdefects in MAO coatings over time. These changes were driven by the interactions between localized corrosion propagation and the accumulation and expansion of corrosion products. Ultimately, neighboring micro-defects merged, forming interconnected through-pores and accelerating MAO coating degradation.
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