The prospects of plasma electrolytic oxidation (PEO) technology applied for surface hardening of aluminum alloys are substantiated. The work aims to optimize the technological process of PEO for aluminum in flowing electrolyte. The design of the equipment and the technological process of the PEO for aluminum deformed alloy D16T in flowing silicate–alkaline electrolyte have been developed. Oxide coatings were formed according to various technological parameters of the PEO process. The properties of the oxide coatings were evaluated, respectively, by measurements of coating thickness, geometric dimensions of the samples, microhardness, wear tests, and optical and scanning electron microscopy. To study the influence of the technological parameters of the PEO process of forming oxide coatings on geometrical, physical, and mechanical properties, planning of the experiment was used. According to the results of the conducted experiments, a regression equation of the second order was obtained and the response surfaces were constructed. We determined the optimal values of the technological parameters of the PEO process: component concentration ratio (Na2SiO3/KOH), current density, flow rate, and electrolyte temperature, which provide the oxide coating with minimal wear and sufficiently high physical and mechanical properties and indicators of the accuracy of the shape of the parts. The research results showed that the properties of oxide coatings mainly depend on almost all constituent modes of the PEO process. Samples with Al2O3 oxide coating were tested during dry friction according to the “ring–ring” scheme. It was established that the temperature in the friction zone of aluminum samples with an oxide coating is lower compared to steel samples without a coating, and this indicates high frictional heat resistance of the oxide coating.

There has been carried out an analysis of methods of oxide covering formation productivity increasing during plasma electrolytic oxidation of aluminum in electrolyte. There has been developed a technology of blank manufacturing and part strengthening by plasma electrolytic oxidation in the electrolyte, as well as the workbench has been modernized. There has been studied the process of oxidoceramic coating synthesis for the D16T aluminum deformed alloy of during plasma electrolytic oxidation in the electrolyte for different process parameters. It is established that the growth rate of oxidoceramic coating can be significantly increased by electrolyte component concentration involved in aluminum oxidation and rational choice of process electrical parameters. Hydrogen peroxide addition leads to obtained oxoceramic coating thickness increasing due to O, O2, OH, OH– concentration increasing in the electrolyte. It is established that the optimal concentration of H2O2 ranges from 5 g/l to 7 g/l.  A further increase of peroxide concentration leads to a decrease in peroxide effect on oxoceramic coating growth rate on the D16T aluminum deformed alloy due to pH changes of the electrolyte and the deterioration of the oxide coating.