ELECTROCHEMICAL POLISHING OF THE AO GRADE ALUMINUM ALLOY IN ACID ELECTROLYTES

Abstract

Aluminum and its alloys are used in a large amount in various industries, in particular mechanical engineering, aircraft building, rocket science, food industry, construction, decor items, jewelry, etc. To improve the corrosion resistance, the surface of aluminum is oxidized, polished or painted. Aluminum polishing is also used for decorative purposes, before applying metal coatings (for example, before chromium, copper, tin plating), to harden the surface and increase the anti-friction properties.

Electrochemically or chemically treated aluminum has a number of very valuable properties, such as improved frictional, mechanical and electrical characteristics. The surface subjected to electrochemical or chemical polishing does not tarnish when anodized. Electrochemical polishing of metals, unlike chemical and mechanical, is more effective. It allows full automation of the process ensuring high quality. Electrochemical polishing is easier to control, since one of its main parameters is the current density, which can be easily changed over a wide range. Despite the high cost of this method, it is widely used for polishing aluminum and its alloys, especially for products of complex configuration, when the use of mechanical polishing is practically impossible.

Electrochemical polishing of pure aluminum and its alloys has been well studied in acidic electrolytes and has a wide industrial application.

This article presents the results of the study of electrochemical polishing of decorative products made of aluminum alloy of the grade A0 in acidic electrolyte. The optimal composition of the electrolyte is chosen, experimental data on the anode treatment of the studied samples are given. The influence of various organic additives as an intensifying metal luster has also been studied.