Corrosion of ZnAl22Cu3 alloy in sodium chloride solution

The structure of the surface layer of ZnAl22Cu3 alloy subjected to a corrosion test in a 3% NaCl solution was tested. Objects of tests: base alloy, alloy with an addition of silicon and alloy with silicon addition modified with rare earth elements. The samples were tested after potentiostatic examinations conducted at approx. 300 mV higher anodic potentials than the corrosion potential for 24 hours. It was found that on the surface of the alloy subjected to the corrosive reaction, a considerable diversity of structure and chemical composition from the surface to a depth of 600 mu m was observed. Dezincification of the alloy surface layer also took place.