In the process of using zinc nickel alloy color passivator, sometimes the passivation film of the workpiece will appear uneven color of black, yellow and blue.What causes this?
According to the field experience and the characteristics of the zinc nickel alloy additive BZ-617 and zinc nickel alloy color passivator Zn-324, Bigolly Technology has analyzed the following four points:
1. The temperature of zinc nickel alloy plating solution is high.When the bath temperature is above 30 ℃, the deposition rate of nickel ions will be faster, so the nickel content in the alloy coating is higher. Generally, the nickel content in the alloy coating is greater than 16%, which will cause uneven passivation color, and the passivation film will appear black or yellow blue.At this time, stop adding BZ-617C nickel supplement, and adjust the nickel ion concentration in the plating solution.
2. The current density of zinc nickel alloy electroplating is high.With high current density, the deposition rate of nickel ions will be relatively fast, which will lead to high nickel ion content in the alloy coating and uneven passivation color.
3. The temperature and pH value of the passivation solution fluctuate greatly.During the production process, large fluctuations in the temperature or pH value of the plating solution will affect the co deposition rate of nickel, thus changing the passivation performance of the alloy coating.The temperature of Zn-324 color passivation solution shall not exceed 30 ℃, and the pH value shall be controlled within the range of 1.8~2.2.
4. The passivation solution is uneven.The color of the passivation film is uneven due to uneven stirring or uneven aeration of the passivation solution.In the production process, the concentration of the passivation solution should be well controlled, so as not to affect the uniformity of the color of the passivation film of the workpiece.
Therefore, in the production of zinc nickel alloy color passivator, if the passivation film of the workpiece appears black or yellow blue due to uneven color, the above four points can be used to quickly solve the problem and reduce the loss caused by the problem.If you are interested in zinc nickel alloy color passivator, please contact Bigolly customer service for free samples and detailed technical information!
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