Chemical Polishing of Aluminum Using Acid-Containing Reverse Microemulsions

Abstract

Chemical polishing of metals using nanostructured media—reverse microemulsions has been studied using the example of aluminum. It has been shown that the surface roughness of aluminum foil reduced after the treatment with reverse microemulsion of sodium bis-(2-ethylhexyi)phosphate in kerosene containing an aqueous solution of hydrochloric acid with a concentration of 0.11 mol/L inside the drops. At a polishing time of 2 h, the average roughness was reduced from 54 to 28 nm. Compositions that do not form microemulsions (aqueous solution of hydrochloric acid, solution of tributylphosphate adduct with hydrochloric acid in kerosene, or dispersion of sodium bis-(2-ethylhexyl)phosphate in an aqueous solution of hydrochloric acid), have not exhibited such an effect. Additional exposure to ultrasound at the same process duration, the introduction of tributylphosphate into the microemulsion, and the replacement of hydrochloric acid with acetic or nitric acid had virtually no effect on the results of chemical polishing.