Hydrogen Release on the Anode in the Course of Plasma Electrolytic Oxidation of Aluminum

The process of preferential hydrogen release on the anode in the course plasma electrolytic oxidation is a result of the thermochemical reaction between aluminum dispersed in spark discharges and water vapor. It is shown that the products of interaction are aluminum hydroxides or oxides. In this case, the degree of oxidation and the maximum efficiency of the plasma electrolytic oxidation are attained in the case of inhibition of the reaction of hydration of the metal and the presence of sufficient amounts of oxygen in the reaction zone. It is discovered that the compounds present in the electrolyte capable of adsorption on aluminum and the cathodic current component suppress the reaction of aluminum hydration and promote the formation of oxides.