Komsomolsk-na-Amure State University, Komsomolsk-on-Amur, Russia

О. V. Bashkov, Head of the Department of Materials Science and Technology of New Materials, Doctor of Technical Sciences, Professor, e-mail: bashkov_ov@mail.ru

Zhao Zidong, Postgraduate Student of the Department of Materials Science and Technology of New Materials, e-mail: 379917387@qq.com
Т. I. Bashkova, Associate Professor of the Department of Materials Science and Technology of New Materials, Candidate of Technical Sciences, Associate Professor, e-mail: telem01@mail.ru

Heilongjiang University of Science and Technology, Harbin, China
Lu Lan, Head of the International Department, Candidate of Technical Sciences, e-mail: lvlan1980@163.com

Harbin University of Science and Technology, Harbin, China

Bao Fengyuan, Associate Professor at the School of Materials Science and Chemical Engineering, Candidate of Technical Sciences, Associate Professor, e-mail: bao5413@qq.com

Microarc oxidation (MAO) is one of the modern, but not widely used methods for forming a valve group of protective oxide layers on metals. The method is most widely used in the oxidation of aluminum, magnesium, and titanium alloys in order to create protective coatings on them. The advantages of the method are the possibility of obtaining sufficiently thick coatings and the environmental friendliness of the process due to the use of low-concentration salt solutions. The mechanical properties and technological parameters of oxide coatings formed on aluminum alloy 7075 by the MAO method have been studied. The coatings were formed on flat samples at different values of current density, oxidation period, and inductance of the electrical circuit. The formation of the research plan and the analysis of the results were carried out using the planning of a full-scale experiment. Optical and electron microscopy methods were used to determine the thickness and morphology of the surface of the oxide coatings. A portable digital meter has measured the surface roughness of the coatings. The microhardness of the coatings according to Vickers was determined in the cross section. It has been found that an increase in the duration of the oxidation period from 60 to 120 minutes with a constant average current density in the electrical circuit of 15.66 A/dm² leads to a monotonous increase in the thickness and roughness of the oxide coatings. The introduction of an inductance in the range of 0.52–53.1 Mh into an electrical circuit changes the shape, filling factor and amplitude of current pulses, and also has a nonlinear effect on the thickness and microhardness of the formed coatings.
The research was conducted at the Central Research Institute “New Materials and Technologies” of the Federal State Budgetary Educational Institution of Higher Education Komsomolsk-on-Amur State University with the financial support of a grant from the President of the Russian Federation for state support of leading scientific schools of the Russian Federation (project NSH-452.2022.4).

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