In the process of using alkaline zinc nickel alloy additives, sometimes the coating will be rough, which affects the coating quality and the effect after passivation. What is the reason?
According to the site experience and the characteristics of the product alkaline zinc nickel alloy additive BZ-617, Bigolly Technology analyzed the following six points:
1. There are solid particulate impurities in the plating solution.When the top of the workpiece is rough, it indicates the existence of solid particle impurities in the plating solution.These solid particles mainly include dust in the air, anode sludge, polished particles brought into the plating solution, hanging debris falling into the plating solution, filter material leakage, high water hardness and internal generation of the plating solution.
2. The bath temperature is too low.Generally, the temperature of plating solution should be controlled at 20~28 ℃.When the bath temperature is low, the conductivity of the bath is poor, the upper limit of current density is reduced, the adsorption of additives is strong, and the desorption is difficult;When the current density is large, the top of the workpiece is easy to burn.
3. The current density is too high.When the current density is too high, the crystal of the coating is rough, the coating in the high current area is easy to burn, and there are many additives, which are brittle and easy to blister.
4. Zinc ion concentration is too high.Zinc ion and nickel ion are the main salt in the plating solution, improving the metal ion required in the plating solution.When the concentration of zinc ion in the bath is too high, the coating will appear dark and rough.Therefore, attention should be paid to analyzing and adjusting the concentration of zinc ion in the plating bath during the production process.
5. The sodium hydroxide content is too low.Sodium hydroxide is a complexing agent in the plating solution and has the function of conducting electricity.When the content of sodium hydroxide is too low, the coating will have rough, dark, anodic passivation, high cell voltage rise, and the dispersion ability and deep plating ability of the plating solution will be reduced, and serious nickel hydroxide precipitation will occur.
6. Too much carbonate in the plating solution.When the concentration of carbonate in the bath is high, the internal resistance of the bath increases, the temperature rise increases, and the upper limit of current density decreases.If the current is slightly higher, the edges and corners of the workpiece will be burnt.
Therefore, the above six points should be paid attention to when the coating is rough in the process of using alkaline zinc nickel alloy additives to reduce the occurrence of faults and improve production efficiency.If you are interested in alkaline zinc nickel alloy additives, please contact Bigolly customer service for free samples and detailed technical information!
If you want to know more about zinc-nickel alloy,you can click to view "Common problem".
