Would you like to carry out a galvanic corrosion study in the laboratory
What is galvanic corrosion?
Galvanic corrosion (or electrochemical corrosion) is a phenomenon that occurs when at least two different metals are brought into contact in the presence of an electrolyte (such as water containing salts, acids, or bases). This creates an electrochemical cell, in which one metal acts as the anode (it corrodes) and the other as the cathode (it is protected).
Galvanic corrosion requires three conditions to occur. First, there must be two different metals, such as aluminum and steel. Second, these two metals must be in direct electrical contact. Third, there must be an electrolytic environment, such as salt water, humidity, or any conductive solution.
In this context, it is the less noble metal, that is, the one that is more electrochemically reactive, that will degrade first: it is the one that undergoes galvanic corrosion.
The FILAB laboratory supports you in the galvanic corrosion study of your materials
Why choose FILAB for a galvanic corrosion study?
FILAB, a laboratory made up of experts in metallurgy and steelmaking analysis, provides its knowledge and expertise to carry out galvanic corrosion studies and the electrochemical characterization of your metal parts.
ANALYTICAL TECHNIQUES
Among the electrochemical techniques used to study galvanic corrosion, the first are:
- the measurement of corrosion potential (Ecorr), which makes it possible to determine which metal acts as the anode or cathode in a galvanic couple. The lower the measured potential, the more likely the material is to corrode. This method is particularly useful for analyzing multi-material assemblies.
- galvanic current measurements consist of bringing two metals into contact in an electrochemical cell and measuring the current naturally generated between them. This makes it possible to directly quantify the intensity of galvanic corrosion.
- the linear polarization technique, also called Tafel or potentiodynamic, which consists of applying a controlled potential variation around the equilibrium point while measuring the resulting current. This approach makes it possible to estimate the corrosion rate as well as the anodic and cathodic reactions involved.
- electrochemical impedance spectroscopy (EIS), a non-destructive method that measures the resistance of a system to alternating current. It provides detailed information on the presence and effectiveness of protective barriers, such as passive films or coatings applied to materials.
Why carry out a galvanic corrosion study?
Évaluer la tenue à la corrosion d’un métal ou d’un alliage
Testing the effectiveness of an anti-corrosion coating or paint
Characterizing passive films on metallic surfaces
Monitoring the degradation of electrolytes, batteries or sensors
Studying diffusive, capacitive, or resistive behaviors in a system
Ensuring the durability and reliability of materials
Optimizing performance and reducing costs
Encouraging innovation and compliance
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our electrochemical analysis services
Measurement of open circuit potential (OCP) in order to assess the spontaneous electrochemical behavior of a metal in a given medium (water)
Galvanic coupling study in order to analyze the interactions between two metallic materials and identify the risks of differential corrosion (e.g. Zinc vs Steel)
Characterization of protective properties: barrier properties, porosity, water permeability, delamination, filiform corrosion…
Impedance measurement to analyze the properties of interfaces between a material and its electrochemical environment
Determination of corrosion rate (LSV) in order to determine the corrosion rate (mm/year) in various environments (salt water, pure water, presence of inhibitors)
Measurement of corrosion potential (polarization curves) by Potensiostat
Development of specific electrochemical tests (cathodic delamination, ACET, edge corrosion, etc.)
How do you distinguish galvanic corrosion from pitting corrosion?
Learn moreFAQ
The study makes it possible to anticipate the risks of premature degradation in metal assemblies, optimize the choice of materials or coatings, and validate metal pairings in demanding environments. It is essential in sectors such as aerospace, space, medical, and energy.
A set of complementary techniques is generally used, including:
The SEM-EDX to visualize the morphology of corroded areas and map the elements.
The XPS to study surface oxidation states.
The ICP-OES to quantify elements dissolved in electrolytes.
And above all, electrochemical tests to measure potentials, currents, and corrosion rates.
The study can be carried out in different contexts:
Field failure (localized corrosion, leakage, breakage...)
Validation of materials or assemblies before industrialization
Comparative study of coatings or surface treatments
R&D project to simulate accelerated aging
At FILAB, we offer tailor-made support :
Advanced surface analysis (SEM-EDX, XPS, FTIR…)
Electrochemical testing (in collaboration with our R&D team)
Interpretation of results and material/process recommendations
Ability to develop specific protocols according to your constraints
