Evaluating the corrosion resistance of Aluminum alloy A6063 with and without protective coatings in a simulated environment proton exchange membrane fuel cells

In this study, Ni-coating and Au/Ni-coating were preparated by electroplating method at room temperature (250 C) and 450 C with various plating time on A6063 alloy substrate. The corrosion behavior of A6063 with and without protective coatings (Ni-coating and Au/Ni-coating) were evaluated in a solution simulating environment of Proton exchange membrane fuel cells (PEMFCs), 0.5 M H2SO4 and 200 ppm HF at temperatures 60 0C. Electrochemical techniques including polarization tests and impedance spectrum are used to evaluate corrosion behaviour. The surface and cross-section morphology, the chemical composition of the specimens were characterized by scanning electron microscope (SEM) and energy-dispersive X-ray (EDS) The results shown that corrosion resistance of specimens coated at room temperature was better than those coated at 450C. Aluminum alloy A6063 with protective coatings significantly improved the corrosion resistance in a simulated environment proton exchange membrane fuel. While, the corrosion current density of the Au/Ni-coating reduced by 6.4 times compared to the Ni-coating and 33.9 times compared to the A6063 without coating.