When we use electroplating nickel additives, sometimes the anode plate will be passivated, resulting in fogging of the nickel plating layer and a decrease in brightness.So, what are the phenomena of anode plate passivation?
Bigolly Technology made an analysis based on the field experience and the characteristics of the product's electroplating nickel additives Ni-301,there are mainly the following four points:
1. The surface of the anode plate is dark brown because Ni2O3 is formed on the surface of the nickel anode plate after passivation.
2. The nickel ion content and pH value in the plating solution will gradually decrease, because the anode current efficiency is lower than the cathode current efficiency after the anode plate is passivated.
3. The tank voltage is higher than that in normal production, and sometimes it is much higher.This is mainly because the anode potential becomes positive after the anode plate is passivated.
4. There is a lot of bubbling on the anode during the electroplating process, and sometimes there is a pungent odor (chlorine gas), and green corrosion products (CuCl2) appear on the copper hook of the anode plate.
In our nickel-plating production process, when the above phenomenon occurs, it means that the anode plate has been passivated.When the anode plate is passivated, the anode plate should be taken out and soaked in hydrochloric acid for brushing to activate the anode plate, and then re-hang it in the plating tank.When the anode area is not enough, the anode area should be increased, and the chloride ion content can be appropriately increased if necessary.However, the chloride ion content should not be too high. When the chloride ion content is too high, the anode dissolves too fast, and the coating will become brittle and peeling.
In the production process of nickel plating, the passivation of the anode plate occurs from time to time.Finding and solving anode passivation in time can reduce failures, improve production efficiency, and enable better use of electroplating nickel additives.If you are interested in electroplating nickel additives,please contact Bigolly customer service to get free samples and detailed technical information!
If you want to know more about galvanizing, you can check "Electroplating encyclopedia".