Fig. 5.

Cross-sectional characterization of the corrosion layers after in vitro degradation. Representative SEM images of the corrosion layers (CL) and corresponding EDX mapping, and line scans following the direction marked by the red arrows (from the outer layer (A) to the inner layer (B) of the corrosion products formed on the ZX00 screw: a) after 3-, b) 6-, c) 14-, d) 21-, and e) 28- days of immersion. Data presented as mean ± standard error of the mean (SEM) (n = 7–9-line scans/time point from 3 independent samples). f) Changes in the corrosion layer thickness as a function of time. Data presented as mean ± standard deviation (n = 150–300 measurements/time point from 3 independent samples); *p < 0.05 versus day 3 and 28. The Kruskal-Wallis test was used for comparison between time points. (The figure should be printed in color).