However, in some surface spots, the Mn-rich layer was visually almost absent, which is also confirmed by the EDX analysis (Figs. S6-S8 in the Supplementary Information). This might suggest the initiation of corrosion and partial delamination of the Mn-rich layer from the surface due to this process. At the same, the instance of corrosion attack was much smaller compared to the case in pure NaCl. The relative fraction of oxygen in the surface layers increased after 24 h of corrosion and was proportional to the amount of Mn on the surface, confirming that the formed layers are mostly hydrated forms of manganese oxides. Fig. . SEM surface morphology of AZ31-4Li (a, d), AZ31-8Li (b, e), and AZ31-12Li (c, f) Mg alloys after 24 h of corrosion in 0.05 M sodium chloride containing 150 mM of permanganate ions.