NMADU Daniel Postgraduate student 1 INFLUENCE OF TEMPERATURE ON MECHANICAL PROPERTIES OF OXIDE FILMS USING HIGH VOLTAGE ELECTROCHEMICAL OXIDATION

Alexander Parshuto, Researcher
unpublished
The High Voltage Electrochemical Oxidation was used to produce an alumina ceramic film on aluminum alloy AMg2. The processing was carried out in oxalic acid as an electrolyte under invariable current and duration for each sample and various anodizing temperatures and current densities. The results were discussed in light of the rate of ionic current flow through the coating during anodic polarization measurements. Introduction. Anodizing is an electrochemical process for producing stable oxide
more » ... ucing stable oxide films on the surface of metals. Anodic coating can be produced on aluminum by using a wide variety of electrolytes with AC, DC or a combination of both. In order to generate an anodic film, the aluminum piece must be the anode and another suitable metal or alloy the cathode. Anodic coatings are classified according to the solvent action of the electrolyte used to produce the anodic film. Some of them are of porous nature as for the example in phosphoric and sulphuric acid electrolytes. Others are essentially nonnporous and are called «barrier layer» films and are generated in ″low solvents power″ electrolytes such as ammonium tartrate and ammonium borate [1]. Anodized aluminum products are suitable for a wild range of applications, not only in the standard field of machinery, aerospace, transport and building industry, but also for the potential use in the area of magnetic storage, photo voltaic solar cells, filters, chemical sensors, photonics and metallic nanowires [2]. Because of the high affinity of aluminum surfaces for oxygen, the metal is always covered with a highly resistant oxide film; the improvement of this natural oxide film to produce an anodic oxide film which is attractively finished, has excellent corrosion resistance and possesses other commercially desirable qualities, is the aim of the anodizing industry today. The type of anodic oxide film that can be produced on aluminum when aluminum is the anode in an electrolytic cell depends on several factors, the most important of which is the nature of the electrolyte [3-5]. High voltage electrochemical oxidation (HVEO) was carried out in this experiment. Material and equipment. In this work flat rectangular plates of aluminum alloy AMg2 (Al-97 wt. %, Mg-2,5 %, Si-0,25 %, Fe-0,4 %, Cu, Mn and Zn-0,1 %) with a total area of 0,2 dm 2 were used. For carrying out the electrochemical oxidation at a high
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