Ultrasmall nanopores obtained by electric field enhanced one-step anodisation of aluminium alloy

The influence of electric fields at different temperatures on the anodic oxide layer growth was studied on AA 5083. Barrier-type alumina layers showed a fair morphology with multiform pores. The diameter of dominating pores performed a transversal amplification from barrier-type layer to pore structure. The pore cells were perpendicular with column constriction near the second-phase particles and parallel with the layer growth. Both the barrier-type oxide layer and porous oxide layer perform excellent corrosion protection on aluminium substrate with the corrosion current density of 10− 10 A/cm2 and transfer impedance of 107 Ω cm2. The former leads to the more effective anti-corrosion property.