Effect of corrosion product films on the in vitro degradation behavior of Mg-3%Al-1%Zn (in wt%) alloy in Hank's solution

Through investigating the corrosion behavior of an as-extruded Mg-3wt%Al-1wt%Zn (AZ31) alloy in a simulated physiological fluid of Hank's solution, it demonstrates that the corrosion process was dependent on the immersion time. Further analyses revealed that the highest corrosion resistance could be obtained at 24 h due to the formation of a compact layer of corrosion products on the sample surface. With increasing the immersion time to up to 48 h, the thickness of surface films increased gradually but obvious de-bonding of such film from the substrate could take place, resulting in a certain resilience of the overall corrosion resistance.