Method: Electrochemical Impedance Spectroscopy
Alternative labels
EIS
Electrochemical Impedance
Description
The Electrochemical Impedance Spectroscopy (EIS) is a non-invasive technique that provide information on corrosion behaviour of metallic surfaces. EIS separates electrochemical processes, allowing to study corrosion mechanisms and measure the protective properties of coatings and patinas. The method used for corrosion studies is the potentiostatic EIS. This technique is based in applying an electical voltage signal (about 10-20 mV) to a system and analysing its intentity response over a specific frequency range (typically from 100 kHz to 10 mHz) to obtain an electrical response, calculating the complex impedance at each frequency. The graphical representation of this function provides the impedance spectrum and its analysis allows the separation of contributions from different elements involved in the corrosion process to obtain information about the mechanisms involved and the protection capacity level of the layers on the surface of the metal (patinas/corrosion products, coatings, inhibitors, etc.)
Techniques
Electrochemical impedance spectroscopy
Type
Analysis method
Version
n/a
Parameters
Type: Frequency (Initial)
Unit: Hz
Value: 100000
Type: Frequency (final)
Unit: Hz
Value: 0.01
Type: Potential
Unit: V
Value: Open circuit potential (OCP)