Institute of Chemistry of Far Eastern Branch of RAS, Vladivostok, Russia:

S. V. Gnedenkov, Professor, Deputy Director on Science, Head of Department of Electrochemical Systems and Surface Modification Processes, e-mail: svg21@hotmail.com
S. L. Sinebryukhov, Assistant Professor, Head of Laboratory of Unstationary Surface Processes, e-mail: sls@ich.dvo.ru
D. V. Mashtalyar, Senior Researcher of Laboratory of Biomedical Composite Coatings, e-mail: madiva@inbox.ru
K. V. Nadaraia, Junior Researcher of Laboratory of Unstationary Surface Processes, e-mail: nadaraiakv@mail.ru

Nowadays, various methods of coatings formation are applied for protection of magnesium alloys from external destructive effects. A method of plasma electrolytic oxidation is developed actively and allows the increasing of anti-corrosion and mechanical characteristics of the treated alloy. It is widely spread in industry due to the results of scientific investigations in the world. Our study shows the results of investigations of electrochemical and mechanical properties and hydrophobicity of composite coating, formed on magnesium alloy MA8 using plasma electrolytic oxidation with further application of polymer on the formed alloy. The polymer is obtained from the telomeric solution of tetrafluoroethylene in pentafluorchlorbenzene. The formed composite coating leads to decrease of the corrosion current density and increase of polarization resistance by two or four orders (in comparison with the basic plasma electrolytic oxidation coating and material without coating, respectively). Extension tests for the samples with composite coating defined the positive influence of thermal impact on overload values under tension. This parameter is increased after the application of tetrafluoroethylene telomers and following thermal treatment. The obtained composite сoating allows have the hydrophobic properties: the contact angle, calculated using the Young-Laplace method for accounting of gravitation deformations of the droplet outline under its own mass was 145 degrees.
This study was carried out with the financial support of the Russian Science Foundation (grant 14-33-00009).

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