In the process of using alkaline zinc nickel alloy brightener, sometimes the pre-treatment of the workpiece is clearly very clean, but after plating the zinc nickel alloy, the coating appears pinhole phenomenon. What is the reason for this?
Based on on-site experience and the characteristics of the alkaline zinc nickel alloy additive BZ-617, Bigley Technology has analyzed the following four points to pay attention to during the electroplating process:
1. The wetting agent content in the plating solution is low. In the alkaline zinc nickel alloy process, the current efficiency of the cathode is relatively low. If the content of the wetting agent is low, the bubbles generated by the reaction are easily retained on the surface of the workpiece, resulting in pinholes or pits. Therefore, wetting agents should be added appropriately during the production process, and the content of packaging wetting agents should be within the range.
2. The cathode current density is too high. When the cathode current density increases, hydrogen evolution on the cathode increases, and pinholes are prone to appear in the coating at high current density areas such as the edges of the workpiece. Therefore, attention should be paid to setting appropriate current density values based on output or area during production.
3. The anode area is small or the distance between the anode and cathode is too close. A small anode area will increase the anode current density, resulting in uneven distribution of electricity on the cathode surface, which can easily lead to pinholes in areas with high current density. If the distance between the positive and negative poles is too close, it can also lead to uneven distribution of power lines, and roughness and pinholes are prone to occur in high current density areas. Therefore, during production, attention should be paid to adjusting the area ratio of the anode and cathode, and ensuring that the distance between the anode and cathode is above 15cm based on the size of the tank.
4. Excessive organic impurities in the plating solution. When the content of organic impurities in the plating solution is high, the brightness of the coating will decrease, and problems such as pinholes, fogging, darkening, and high brittleness will occur. In severe cases, problems such as negative and positive surfaces and poor adhesion of the coating will occur. Therefore, active carbon should be regularly used to treat organic impurities in the plating solution during the production process.
So, when we use alkaline zinc nickel alloy brightener to cause pinhole phenomenon in the coating, we need to pay attention to the above four points during the electroplating process to reduce the occurrence of faults. If you are interested in alkaline zinc nickel alloy brighteners, please contact Bigley customer service for free samples and detailed technical information!
If you want to learn more about nickel plating, you can click to view the "Common problem".
