Passivation

Chrome (III) Systems - Secure Your Advantage

Based on the EU End-of-Life Vehicle Directive, manufacturers of metal components are required to switch surface coating to passivation without chrome-VI (chromate coating). Duscher Galvanotechnik GmbH is already prepared for this challenge.

Based on close collaboration with the development departments of several renowned expert companies, we introduced this future-oriented process. Using selected processes all required standards are not only achieved, but also exceeded! The new chrome-VI-free thick-film passivations show very high temperature resistance. Corrosion protection remains intact even at extreme temperature loads of up to 200 °C.

We are able to offer chrome-VI-free passivation for zinc, zinc-iron and zinc-nickel processes.

Aluminium and Magnesium Processing

For many years, aluminium and magnesium have been increasingly used in the automotive industry. As sheet metal formed parts or as casting material the application areas have multiplied in the last years in various alloy variants. In view of the current CO2 debate and the advantage of reducing weight compared with steel, aluminium and magnesium will continue to gain in significance.

The material-specific attributes of aluminium and magnesium often demand special surface treatment processes, without which further use would not be possible at all. Hereby, the technology of cleaning and passivation (caustic passivation) has special importance. Having recognized the potential of these materials we started expanding our capacities in March 2009.

Caustic passivation has established itself as pre-treatment prior to painting, welding or gluing. Our process sequence is capable to achieve the special requirements for cleanliness and water wettability of the treated surfaces.

Cleaning of Aluminium and Magnesium Components

Surface treatment starts with cleaning of the surface. The success of the entire process depends on this step, as only surfaces free from grease and oxide ensure adhesive metal surfaces. Thus, the cleaning and activation process must be exactly tuned to surface consistency and degree of contamination of the respective base material.

Our alkaline, neutral and acid dip cleaners and/or electrolyte cleaners meet this requirement. Their result is free from greases and oils and can be processed without process interferences.

Passivation of Aluminium and Magnesium Components

Aluminium as well as magnesium characteristics can be optimized using chrome-VI-free processes. By substituting chrome-VI we comply with the requirements of the EU End-of-Life Vehicle Directive as well as of the Directive for Electronic Scrap. ChromitAL®TCP is a chrome-VI-based passivation.

Caustic Passivation of Aluminium Components (Ti / Zr Conversion Coating)

At DGT Duscher Galvanotechnik GmbH aluminium characteristics can be optimized using a chrome-VI-free process based on titanium / zirconium. By substituting chrome-VI we comply with the requirements of EU Directives. This coating temporarily protects aluminium surfaces against oxidation. This is an essential prerequisite for good weldability.

The extremely low contact resistance in the µOhm range recommends these films for applications in electrical engineering as well. The application can also be used without rinse (no-rinse). As this process does not use any hazardous substances, it can be used for food containers as well. This process is not only cost-effective, but also efficient and very well suited as optimum adhesive base for paints and adhesives.

Advantages

Further information is available upon request. We are looking forward to assist you!