Effect of Grain Refinement on the Electrochemical Behavior of Pure Copper by Employing Mott–Schottky Analysis in Conjunction with Point Defect Model

This work aims at studying the influence of grain refinement on the electrochemical behavior of pure copper by employing Mott–Schottky analysis in conjunction with point defect model (PDM). Microstructural evaluations revealed that the mean grain size decreased from about 26 μm for the annealed sample to about 190±20 nm after four passes of accumulative roll bonding (ARB). Compared to the annealed sample, the electrochemical impedance spectroscopy (EIS) revealed that the polarization resistance increased from about 49.63 kΩ.cm2 to 94.97 kΩ.cm2 for Ultra-fine grained (UFG) pure copper after four passes of ARB. Also, the semiconductor properties of the samples were investigated by employing Mott–Schottky analysis in conjunction with PDM. All electrochemical tests showed that the electrochemical behavior of pure copper is improved under influence of ARB process, mainly due to the formation of thicker and less defective oxide film.