A combined AC/DC spark anodization technique has been employed in this work to form a protective, silica-coated, oxide coating on the Al-Cu alloy AA2219 (6 wt% Cu). The use of a range of surface techniques has revealed that the oxide film becomes thicker, more glassy, and less porous with increasing applied current density as well as with longer anodization times, giving improved oxide film passivity and corrosion resistance, even without the use of any surface post-treatment methods, such as pore sealing. Although the total oxide film thickness increases roughly linearly with increasing total anodization charge density, the barrier film thickness and the porosity of the outer layer seem to plateau at above ca. 150 C/cm(2), suggesting that this is the optimum charge density for the protection of AA2219 from corrosion. Also, the oxide film growth rate and the charge efficiency are found to be as high as 2.7 mu m/cm(2) and 43%, respectively, better than what has been reported for the spark anodization of other Al alloys. Importantly, under all anodization conditions investigated here, the Al2Cu intermetallics are retained in the underlying alloy, thus maintaining the alloy strength. (C) 2013 The Electrochemical Society. All rights reserved.