Conversion Coating
The conversion layer forms through chemical or electrochemical reactions on the surface of metals and improves adhesion and corrosion resistance.
Physicochemical mechanism of action
The conversion layer forms when the surface of a metal comes into contact with a treatment liquid. Chemical compounds on the surface react and form a new layer of different materials.
Metallurgical relevance & risks during welding
The conversion layer improves adhesion of paints and coatings, enhancing overall bond strength. It also protects against corrosion by forming a barrier. However, a missing or too thin conversion layer can cause paint to not adhere properly and increase corrosion susceptibility.
Workshop practice & instructions
To create an effective conversion layer, the metal surfaces must be thoroughly cleaned before treatment. Temperature and time of treatment should be precisely maintained to achieve the desired layer thickness. Incorrect parameters can result in an incomplete or overly thick layer, negatively affecting adhesion and corrosion resistance.