The influence of the ultrafine-grained structure on passivation of copper

The influence of ultrafine-grained structure on passivation of copper in borate solutions was studied. Ultrafine-grained cooper was prepared by the equal channel angular extrusion. It was shown that, under the conditions of anodic oxidation, an oxide film with improved protective properties is formed on the ultrafine-grained sample. This film is characterized by a small thickness, low roughness, and high content of copper(I) oxide.