Verdigris

In surface technology, verdigris is an undesirable phenomenon that occurs when copper and copper alloys corrode. It is a green to blue-green patina that forms on the surface of the metal over time. Verdigris is caused by the oxidation of copper, especially in humid or acidic environments, and consists mainly of copper(II) acetate and copper(II) carbonate.

Although verdigris is often considered an aesthetic problem as it can affect the appearance of copper surfaces, it also has an impact on the structural integrity of the metal. The patina forms a protective layer on the surface that protects the underlying copper from further corrosion. However, a heavy accumulation of verdigris can lead to an uneven surface finish and in some cases compromise the integrity of the metal surface.

Various methods are used in surface technology to prevent or control the occurrence of verdigris. A common strategy is to apply protective coatings to copper surfaces to seal the surface and protect it from moisture and aggressive environments. These coatings can be lacquers, varnishes, waxes or special anti-corrosion agents that are applied to the surface.

In addition, various cleaning and maintenance methods can also be used to remove existing verdigris and restore the appearance of the copper surface. This can include the use of mild detergents, abrasives or special removal solutions that gently remove verdigris from the surface without damaging the underlying metal.

Overall, verdigris is a common problem in surface technology, particularly in the processing of copper and copper alloys. However, by using appropriate protection and cleaning methods, manufacturers can control the formation of verdigris and maintain the quality and aesthetics of copper surfaces.