Determining the influence of parameters of electrochemical polishing of aluminum alloys on roughness and surface reflectivity

Aluminum-based alloys are applied in a wide variety of sectors: construction, aircraft and ship construction, car industry, furniture industry, oil and gas industry, power engineering, and fuel industry. One of promising methods of treating parts from aluminum alloys is electrochemical polishing, creating the esthetic surface texture by achieving high reflectivity and low roughness. Low production cost, high performance, and no dirt from polishing pastes on the surface are critical advantages of electrochemical polishing of aluminum alloys over mechanical polishing. However, its disadvantages are failure to treat parts consisting from different metals and alloys, namely no universal electrolyte. The authors studied electrochemical polishing of aluminum alloys with the electrolyte, containing ethyl alcohol and chloric acid. The article describes the studied influence on a volumetric ratio of the electrolyte components on the quality of finished surfaces of aluminum alloys AD1, AD31, AMg6 and D16. The authors studied the influence of process temperature, duration, and voltage supplied to the cell on roughness and reflectivity of the surface of the alloys under study. It has been determined that the most glossy surface with minimum roughness is achieved, when treating them in the electrolyte with a volumetric ratio of HClO4:C2H5OH = 1:4 at 10 oC. The article describes the analysis of profilograms of treated surfaces of the alloys under study. It has been found that electrochemical polishing does not smooth surface macrodefects. Polishing contributes to achieving a more uniform surface structure as proved by the obtained micrographs.