The effects of scandium, yttrium, and lanthanum on corrosion and electrochemical properties of zinc alloy ZAMg4.5-2

Abstract

In this work, the main electrochemical characteristics of the zinc alloy TsAMg4.5‑2 with scandium, yttrium, and lanthanum in a NaCl electrolyte medium were determined using the potentiostatic method in the potentiodynamic mode at a potential sweep rate of 2 mV/s. Studies on the corrosion–electrochemical behavior of a zinc alloy showed that the potentials of free corrosion, pitting formation, and repassivation of alloys shifted to a positive region with an increase in the concentration of a rare-earth metal. Meanwhile, alloys doped with small additives of specified elements (0.1–0.5 wt.%) were characterized by increased corrosion resistance. The decrease in corrosion rate was associated with the passivation process of alloys. With an increase in the concentration of chloride ions in the NaCl electrolyte, the potentials of corrosion and pitting formation shifted to the negative region, whereas the corrosion rate of the alloys increased.