Improvement of the Corrosion Resistance of Aluminium Alloys Applying Diff erent Types of Silanes - Advanced Materials for Agriculture, Food and Environmental Safety - page 49

Figure 2.10 SEM of surface for anodized AA-2024 with HTS and treated with a mixture
of bis-amino silane and bis-sulfur. h e surface is completely covered.
Figure 2.11 SEM of the FIB cross-section for anodized AA-2024 + HTS and treated with
a mixture of bis-amino silane and bis-sulfur (20000x), anodic layer ≈ 3.6 μm, sealing layer
is very thin. Complete i lling of pores. Conversion layer is very thin.
h e obtained EDX analysis results are shown in Table 2.5. h e chemi-
cal composition (wt% and at%) of TSA-anodized AA2024 specimen pres-
ents higher oxygen contents due to alumina formation, while sulphur was
incorporated from the bath into the anodic layer (which contained H 2 SO 4
and Al 2 (SO 4 ) 3 ). No copper could be detected here. h e oxygen percentage
content is higher for both sealed specimens due to hydration of the anodic
layer during the sealing process.
h e inl uence of the treatment time and the bis-sulfur silane concentra-
tion on surface i lm composition was systematically studied (Figure 2.12).
It could be observed that the times of sealing as well as the silane concen-
tration in the bath have a great inl uence on the results obtained.