Enhanced performance of the AA2050-T8 aluminium alloy following excimer laser surface melting and anodising processes

The potential of laser surface melting (LSM) as a pre-treatment prior to conventional anodising has been evaluated on an AA2050-T8 (Al-Cu-Li) aerospace alloy. A KrF excimer laser was utilized, of wavelength of 248 nm, with variation of the number of pulses received per unit area. After LSM, the specimens were anodised at a constant voltage of 12 V in 0.46 M sulphuric acid for 240 s. Material characterization, in terms of surface morphology, microstructure and phase transformation, was performed using scanning and transmission electron microscopies, interferometry and scanning Kelvin probe force microscopy (SKPFM). The corrosion behaviour was evaluated based on the standard ASTM G34-01 EXCO test, revealing the distinct improvement in performance of the combined laser and anodising treatments. (C) 2009 Elsevier B.V. All rights reserved.