AC-electrochemical cleaning versus AC-anodising of aluminium

AC-electrochemical cleaning and AC-anodising of rolled AA1050 in phosphoric acid have been investigated under constant AC-current conditions. Inductiv ely coupled plasma optical emission spectrometry (ICP-OES) and potential re sponse measurements demonstrate the transition from AC-anodising to AC-clea ning for different electrolyte concentrations and current densities. The me chanisms of the anodic and cathodic reactions reveal themselves in the resp ective potential responses. With TEM a thin non-porous oxide film of less t han 10 nm is observed on the AC-cleaned substrate. AES depth profiling reve als the presence of remnant phosphorus from the electrolyte in the thin sur face oxide layer.