Oxide formation on aluminum alloys in boiling deionised water and NaCl, CeCl3 and CrCl3 solutions

Abstract

Rutherford backscattering spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy have been employed to provide depth, surface chemical and morphological information respectively for a range of Al-alloys treated for 2 h at 90-100 °C in either deionised water (DIW), 30 mM NaCl, 10 mM CeCl3 or 10 mM CrCl3 solutions. Alloys included Al sheet 1100-O, 2024-T3, 3004-H19, 5005-O, 6061-T6 and 7075-T6. In DIW all alloys developed the same oxide thickness with a boehmite-like appearance. In NaCl and CeCl3 solutions the oxide thickness varied with alloy composition but was considerably thicker than the deionised case and maintained a boehmite-like appearance. Ce was distributed ..