Application of Galvanostatic Non-Linear Impedance Spectroscopy to the Analysis of Metallic Material Degradation.

This study presents a novel application of Non-Linear Electrochemical Impedance Spectroscopy (NLEIS) in galvanostatic mode for the rapid, non-destructive assessment of metal degradation. By using galvanostatic mode instead of traditional potentiostatic methods, polarization-related challenges are mitigated, enabling more accurate and reliable analysis. The technique allows for the determination of corrosion rates (corrosion current) and material susceptibility to oxidation (Tafel coefficient) through a single measurement with a modulated AC perturbation signal. Theoretical assumptions of the method were validated through tests on both a non-linear model system and an experimental system. The proposed research methodology is highly effective for monitoring the condition of metallic materials in various environments, covering both anodic and cathodic processes.