Electrochemical Behavior of Sintered CuAg4 at. pct Alloy

The electrochemical characteristics of sintered CuAg4 at. pct alloy in different stages of synthesis and thermomechanical treatment were examined by cyclic voltammetry in a NaOH medium. On the voltammograms recorded at the sintered alloy, six current waves can be noticed at the anodic part, and six corresponding current waves are observed at the cathodic part. A possible electrochemical reaction is attributed to each wave. The effect of the potential reversing limit was used to distinguish the correlation between the anodic and cathodic peaks. After the deformation with 60 pct deformation degree, the alloy becomes more corrosion resistant, whereas the corrosion mechanism remains the same as before mechanical treatment. Subsequent anneal of the deformed alloy at 533 K (260 °C) for 150 minutes leads to the hardening effect. At the same time, the alloy remains corrosion stable, and some of the current waves present at the other voltammograms are hardly noticeable here. Also, we propose our own model of oxide layer formation on the surface of a Cu-Ag alloy.