Atomic layer deposition of nanometric alumina for corrosion protection of heterogeneous metallic surfaces: the case of aeronautical grade aluminium alloy 2024-T3

Abstract

Nanometric layers of Al2O3 were applied by atomic layer deposition (ALD) on 2024-T3 aluminium alloy. The ALD layers suppressed the corrosion of the alloy as confirmed by Scanning Kelvin Probe Force Microscopy (SKPFM), polarization curves and Electrochemical Impedance Spectroscopy (EIS). The protection provided by the ALD layers weakened with the time of immersion and this was attributed to the incorporation of hydroxyl species in the film during the deposition at low temperature (100 ◦C) making them vulnerable to water.