**4. Conclusions**

In this study, the corrosion resistances of the AA2024-T3 and the AA2524-T3 alloys were compared. The differences between these alloys are the number and the precipitates' area fraction. The AA2024-T3 alloy has a smaller number of IMCs, which, however, are larger than those found in the AA2524-T3 alloy. Therefore, the IMCs area fraction of the former is higher than the latter. The SEM results sugges<sup>t</sup> that the rapid removal of active sites from the AA2524-T3 surface (smaller IMCs) promotes a cleaner surface.

The hypothesis that defective areas prone to electrochemical reactions were removed from AA2524-T3 was confirmed by the EEC fitting to EIS results, as AA2524 *R*ox increases and CPEox decreases with immersion time. Additionally, the corrosion process of AA2524, represented by *CPE*cor, "*α*cor" and *R*cor, are significant only up to nine hours of exposure and confirm the higher contribution of active sites of the surface, caused by partially soluble corrosion products.

The electrochemical tests also showed that the localized corrosion resistance of the AA2524-T3 was higher than the AA2024-T3 during the whole test period. This was indicated by the higher impedance values associated with the first alloy and confirmed by surface observation after various immersion periods in the tested electrolyte. On the other hand, SEM analysis showed that the corrosion attack on the AA2524-T3 alloy surface was faster due to its larger number of small particles.

**Author Contributions:** Conceptualization, I.C. and H.G.d.M.; methodology, F.M.Q. and M.T.; validation, I.C. and H.G.d.M.; formal analysis, F.M.Q. and M.T.; investigation, F.M.Q., M.T. and A.F.S.B.; writing—original draft preparation, M.T. and A.F.S.B.; writing—review and editing, M.T. and A.F.S.B.; visualization, I.C. and H.G.d.M.; supervision, I.C.; project administration, I.C.; funding acquisition, I.C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by CNPq, grants number 400895/2014-5, 400781/2013-1 and 158764/2014-5 and CAPES, gran<sup>t</sup> number 1536157.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** The authors acknowledge CNPq and CAPES.

**Conflicts of Interest:** The authors declare no conflict of interest.
