The aim of this work is to study th

The aim of this work is to study the influence of pulsed current on hard anodizing process (in sulphuric acid bath)
of AA 7075-T6, a commercial heat treated aluminium alloy widely used in several innovative and strategic
mechanical sectors (military, automotive, aerospace, etc).
Exploiting different pulsed current procedures (slow square pulse mode), combining different duty cycles
and current levels it was possible to obtain thick and hard anodic oxides with a good interfacial adhesion.
The optical microscopy characterization shows that the use of pulsed current minimizes the growth of
defects at the oxide/alloy interface caused by the presence of intermetallic precipitates characteristic of
AA 7075-T6. Moreover nano-indentation profiles, evaluated along the coatings cross section, highlight
the oxide hardness increase of the samples obtained employing pulsed current cycles (PC) compared to
those obtained with standard direct current process (DC) or multistep direct current procedures (MSDC).