Investigation of the trivalent-chrome coating on 6063 aluminum alloy

In this work, the green trivalent chromium coating on 6063 aluminum alloy surface was made and studied by means of trivalent chromate compound (KCr(SO4)2) as inhibitor. The coating was evaluated in 3.5 wt.% NaCl at room temperature using polarization curve, AC impedance spectroscopy (EIS). The results show that the trivalent chromium compounds treated surface presents better corrosion behavior in chloride media than the original material surface. The morphologies and composition and valence state of the coating were examined by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS), respectively. The result indicates that the trivalent chromium chemical conversion coating was made on aluminum alloy surface.