This study surveyed the amount of dissolved aluminum, reflectance of aluminum surfaces, and thicknesses of the anodic oxide films after electropolishing under conditions of several solution temperatures and current densities. Based on results obtained when phosphoric-sulfuric acids were used on pure aluminum A1050, we assessed electropolishing effects on surface structures and specular glosses.
Results show the optimum conditions for electropolishing of pure aluminum: current density at 60 °C that is greater than 0.113 A/cm² and greater than 0.151 A/cm² at 80 °C. Moreover, electropolishing of pure aluminum with current density 0.151 A/cm² at 80 °C can provide flat, smooth surfaces having both high reflectance and specular gloss, creating almost no anodic film.