Composition and barrier properties of plasma electrolytic protective coatings on aluminum alloys used in marine technology

Aluminum alloys are increasingly used in marine technology for the construction of ship hulls and their superstructures, as well as for the manufacture of various marine equipment, piping, and other devices. However, the use of aluminum alloys in structural elements exposed to direct contact with seawater requires further study and the development of measures to improve anti-corrosion and tribological characteristics. The formation of protective coatings on the surface of aluminum alloys by the method of plasma electrolytic oxidation makes it possible to increase anti-corrosion and tribological characteristics. The paper represents the results of a study aimed to estimate the effect of the duty cycle (D) during plasma electrolytic oxidation (PEO) on morphology, chemical composition and barrier properties of coatings obtained on AMg3 aluminum alloy. The study revealed that an increase in the duty cycle of the polarizing signal leads to an increase in thickness and decrease in porosity of the coatings along with an improvement of the corrosion protection performance of the treated alloys.