Development and Characterization of an Advanced Passivation Plant
Aluminum is a highly relevant technical material. Its use is increasing continuously in numerous industrial sectors due to its low weight and high formability. In many cases, aluminum surfaces are modified using chemical and electrochemical processes in order to protect against environmental influences and corrosion. A well-established approach is to use aluminum conversion layers, which form a chemically bound protective and adhesion layer on the metal surface.
For many decades, chromate conversion coatings containing hexavalent chromium (Chromium VI) were considered the standard process for corrosion protection and as an adhesion promoter for subsequent coatings. However, due to regulatory requirements (e.g., REACH) and increasing demands regarding environmental and occupational safety, chromium(VI)-free systems are now required that provide equivalent or superior performance in terms of protective effect and process robustness.