Study of deoxidation of 2024-T3 with various acids

Sheet aluminium 2024-T3 alloy was treated in a range of acid solutions. These acid solutions included HNO3, H2SO4, and H3PO4 alone, with HF, and with a combination of the oxidant sodium persulphate (Na2S2O8) and HF. Changes in the surface chemistry and morphology of the matrix and intermetallics were characterised by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDXS), Rutherford backscattering spectroscopy (RBS), and X-ray photoelectron spectroscopy (XPS). Etch rates for each acid solution were determined by weight loss after repeated immersion. In addition, the acid solutions were analysed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) to determine the amount of aluminium and alloy component dissolution.