Beschreibung:
<jats:p>The corrosion behaviour of epoxy coatings electrodeposited on aluminium, as
well as on electrochemically and chemically modified aluminium were
investigated during exposure to 3 % NaCl. Electrochemical impedance
spectroscopy (EIS) and thermogravimetric analysis (TGA) were used for the
determination of the protective properties of epoxy coatings on aluminium,
anodized aluminium, phosphatized and chromatized-phosphatized aluminium. The
protective properties of epoxy coatings on anodized and
chromatized-phosphatized aluminium are significantly improved with respect
to the same epoxy coatings on aluminium and phosphatized aluminium: higher
values of the pore resitance and charge-transfer resistance, lower values of
the coating capacitance, double-layer capacitance and relative permittivity
(from EIS) smaller amount of absorbed water inside the coating (From TGA).
On the other hand, the lower values of the ipdt temperature indicate a lower
thermal stability of the epoxy coatings on anodized and
chromatized-phosphatized aluminium.</jats:p>