Z.F. Narzulloev, J.N. Aliev, I.N. Ganiev

Annotation:

This paper examines the effect of small nickel additions (0.01–0.5 wt.%) on the corrosion-electrochemical properties of Zn5Al and Zn55Al zinc-aluminum alloys in NaCl solutions with concentrations of 0.03 and 3.0 wt.%. The studies were conducted under controlled conditions to evaluate the stability of the alloys in environments simulating atmospheric and marine corrosion. The free corrosion potential (Efreecor.) was recorded for 60 min after immersion of the samples in the electrolyte—this time is sufficient for stabilization of the electrochemical parameters and formation of the primary oxide film on the surface. It is shown that the introduction of nickel consistently shifts the free corrosion potential toward the positive region, especially in a dilute NaCl solution, indicating an increase in the thermodynamic stability of the alloys. This is likely due to changes in the structure of the surface layer and a decrease in the activity of the anodic sites. Increasing the chloride ion concentration increases the corrosion rate and leads to a negative potential shift, as chloride ions actively destroy protective films and stimulate localized corrosion processes. Паёми политехникӣ. The obtained data allow us to optimize the alloy composition for use in various aggressive environments.

Keywords: zinc-aluminum alloys, nickel, free corrosion potential, NaCl, anodic polarization, corrosion resistance