Influence of copper additives on the corrosion-electrochemical behavior of high purity zinc in the medium of electrolyte NaCl

Modern scientific and technological progress contributes to the development of non-ferrous metallurgy at a high rate. In the total production of non-ferrous metals, which are widely used in industry, zinc ranks fourth. Due to the specific properties, zinc and its alloys are widely used as structural and non-structural products. A significant part of the metal zinc produced is used for covering metal sheets with them, for the manufacture of semi-finished products and shaped castings. In recent years, zinc-based alloys have been widely used for the manufacture of cast protectors used to protect marine vessels and structures from corrosion. The expansion of the fields of use of zinc products pose new challenges for specialists engaged in the production and use of new zinc-based alloys. One of the alloying additions of zinc alloys is copper. It is reported that copper (up to 0.6 wt.%) Increases the hardness and degrades the ductility and corrosion resistance of zinc. The copper content in wrought zinc alloys reaches up to 5.5 wt%. Due to conflicting facts regarding the effect of copper on the corrosion resistance of zinc. In this regard, we investigated the effect of its additives up to 2.0 wt.% On the corrosion-electrochemical behavior of high-purity zinc in an electrolyte NaCl. The studies were carried out by a potentiostatic method (potential sweep rate 2 mV/s) on a PI-50-1.1 pulse potentiostat. It was found that alloying zinc with copper up to 2 wt.% Increases its corrosion resistance by 10-15%, in an electrolyte environment of NaCl. The increase in the corrosion resistance of alloys of the Pb-Cu system is accompanied by a shift in the positive direction of the ordinate of the main electrochemical potentials.