Common problem

Why do the products produced by zinc plating trivalent blue passivation appear whitish and foggy?

2022-01-14

    In the production process of using zinc plating trivalent blue passivation, sometimes the film layer of the workpiece will appear partial whitening, like fogging. How to solve this phenomenon?

    Bigolly Technology made the following analysis based on the field experience and the characteristics of the zinc plating trivalent blue passivation BZ-212 product,There are many reasons for the appearance of white fog,it is necessary to pay attention to the links from pretreatment, bath maintenance to passivation treatment.


    1. Incomplete degreasing in pretreatment: If the degreasing in pretreatment is incomplete, the plating solution will be polluted, the performance of the plating solution will be deteriorated, and the workpiece will appear foggy and flowery due to the adhesion of oil stains.

    2. Improper maintenance of the plating solution: If the performance of the galvanized brightener is not good, or the galvanized brightener is added too much, or there are too many organic impurities in the plating solution, it is easy to make the galvanized layer fog.When there are heavy metal impurities such as lead and copper in the plating solution, the general content exceeds 5mg/l, there will be obvious fogging phenomenon.

    3. The chemical polishing solution has not been replaced: it is generally required to use 2-3% nitric acid for polishing. If the chemical polishing solution is used for a long time, the accumulated zinc ion concentration is too high, or the acidity of the chemical polishing solution is too low, which will affect the chemical polishing of the plated parts. quality, resulting in fogging of the coating.

    4. The blue zinc passivation solution is unbalanced: the pH value in the passivation solution is too high, and the acidity is too low, which is easy to form passivation fog.In addition, after long-term use, the accumulation of Zn2+ and Cr3+ in the passivation solution is too high, and it is easy to form the passivation layer and fog.

    Therefore, we need to pay attention to the above four points in the production process of using zinc plating trivalent blue passivation,It can effectively reduce the occurrence of failures and improve production efficiency.If you are interested in zinc plating trivalent blue passivation, please contact Bigolly customer service, you can get free samples and detailed technical information!    

    If you want to know more about copper plating, you can check "common  problem".