Electrolytic polishing solution for aluminum or aluminum alloy and electrolytic polishing method

Abstract

An electrolytic polishing solution for aluminum or aluminum alloy and an electrolytic polishing method. The electrolytic polishing solution comprises 18%-48% of H2SO4, 20%-43% of H3PO4, 5%-20% of PEG, 6%-18% of C4O6H4KNa and the balance of water. The electrolytic polishing solution provided by the invention contains no nitric acid or chromic acid, and is favorable for environmental protection. The polishing solution has obvious advantages in quality and price compared with other polishing solutions. Due to flexible ratio, the polishing solution has good industrial operability. The electrolytic polishing solution is especially suitable for electrochemical polishing on hard aluminum alloy workpiece requiring high surface quality, and endows full gloss (high brightness of the polished workpiece) on the surface of aluminum or alloy thereof, while smoothening the surface at the same time. Besides, the electrolytic polishing solution has certain leveling effect on the workpieces without mechanical polishing.

Description

technical field [0001] The present invention relates generally to methods of electropolishing aluminum or aluminum alloys, and more particularly to electropolishing fluids used in the methods. Background technique [0002] Electrochemical polishing has always played an important role in the surface finishing of aluminum products. At present, while smoothing the surface of aluminum and its alloys, an electrochemical polishing solution that can give sufficient gloss can be used. Electrochemical polishing of aluminum and aluminum alloy workpieces often uses the three-acid method (sulfuric acid-phosphoric acid-chromic acid) or phosphoric acid-nitric acid method. However, the three-acid polishing process has disadvantages such as poor operating environment, carcinogenic chromium ions brought out due to hydrogen evolution at the cathode, high viscosity of the polishing solution, and a large amount of workpiece brought out during polishing; During the process, toxic nitrogen oxide...