In the process of using nickel plating additives, sometimes the contact point between the workpiece and the copper hook of the hanger will be dark and black. What is the reason?
According to the site experience and the characteristics of the nickel plating additive Ni-301, Bigolly Technology analyzed the following three main reasons:
1. The dispersion ability of the plating solution is too poor.The main reasons for the poor dispersion ability of the plating solution are the imbalance of the composition content of the plating solution, such as high nickel sulfate content, low chloride ion content, and poor conductivity of the plating solution;Or the pH value of the plating solution is low, the temperature is high, and the current density is low.When the dispersion ability of the plating solution is poor, the current of the workpiece at the hook position is relatively small, so the coating of the workpiece will be relatively thin, and it is easy to appear gray and black.
2. The content of copper impurities in the plating bath is high.In the nickel plating bath, the content of copper impurities cannot exceed 5mg/L, otherwise the coating of the workpiece in the low current area will be dark, or even black.Because of the concealed function of the copper hook, it will eat part of the current. If the content of copper impurities in the plating solution is high, the coating at this part is easy to blacken.
3. The content of softener and brightener is out of balance due to improper use of nickel plating additives.When the ratio of softener and brightener in the plating solution is out of balance, the crystallization and brightness of the coating will be seriously affected, and there will be darkening at the hook.
Therefore, when the contact point between the workpiece and the copper hook of the hanger appears dark and black during the use of the nickel plating additive, we can timely eliminate the cause of the fault according to the above three points to reduce the loss caused by the fault.If you are interested in nickel plating additives, please contact Bigolly customer service for free samples and detailed technical information!
If you want to know more about nickel plating,you can click to view "Common problem".