Passivations / Topcoats

Passivation Processes

Passivation of zinc-plated components is applied to enhance corrosion resistance and improve the visual appearance of the product. During this process, a thin chromate layer forms on the zinc coating, protecting the underlying material from corrosion and significantly extending its service life.

We offer the following passivation processes:

  • Blue (clear) passivation
    Cr³ passivation compliant with the RoHS directive
  • Thick layer (dickschicht) passivation
    Cr³ passivation compliant with the RoHS directive
  • Cobalt-free passivation
    Cr³ passivation compliant with the RoHS directive
  • Black (Cr³) passivation*
    Cr³ passivation compliant with the RoHS directive

* Black passivation with Fixcoat® (optimized process)
Our black passivation process based on trivalent chromium, combined with Fixcoat®, is a uniquely optimized treatment developed in-house. This process results in a uniform, deep black, color-stable finish with exceptionally high corrosion resistance.

With performance exceeding 720 hours in neutral salt spray testing, this treatment can compete with zinc-iron and even zinc-nickel coatings, making it a full-fledged alternative. In contrast to conventional Cr³ black passivation systems — which typically offer lower corrosion resistance, may leave an undesirable powdery residue, and result in a less refined appearance — our process delivers a clean, non-greasy, and durable finish of superior quality.

This process is fully compliant with the RoHS directive and free from hexavalent chromium.

Topcoats

The use of topcoats on electroplated zinc coatings has increased significantly in recent years. These additional treatments are applied to further optimize specific properties of the zinc layer.

Topcoats can contribute to:

  • Improved corrosion resistance
  • Increased temperature resistance
  • Controlled coefficient of friction

In practice, enhanced corrosion protection is the primary reason for applying a topcoat.

For both rack plating and barrel plating, we offer this treatment as an optional addition within our process.

Want to know more?

Would you like more information about our processes or tailored advice? Please feel free to contact us. We are happy to assist you and think along with your requirements.
 

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