When we use nickel sealing additives to produce, to obtain a good nickel sealing coating, the preparation sequence of the plating solution is very important.So how should the plating solution be prepared?
Bigolly Technology made an analysis based on the field experience and the characteristics of the product's nickel sealing additives Ni-351,share the correct preparation method of the plating solution：
1. Add about 1/2 of the total volume of water into the plating tank and heat it to 50~60℃.
2. Add the calculated amount of nickel sulfate and nickel chloride, and stir until completely dissolved.
3. In another tank, heat 1/5 of the water of the plating solution to 80°C, add the calculated amount of boric acid, stir until it is completely dissolved, and set aside.
4. Adjust the pH of the plating solution to 3.0 with 10% dilute sulfuric acid, add 2~3ml/L of hydrogen peroxide, and stir for 30 minutes.Then, the pH value of the plating solution is adjusted to 5.5-6.0 with nickel carbonate solid powder, the temperature is raised to 65-70° C., and the temperature is maintained for 30 minutes to precipitate metal impurities in the plating solution.
5. When the water temperature is 50~55℃, add 2g/L of activated carbon, stir well for 30 minutes, and filter after standing for 2 hours.
6. Filter the dissolved boric acid into the plating tank.
7. Add water to the predetermined volume of the plating tank, adjust the pH of the plating solution to 3.0 with 10% dilute sulfuric acid, and control the temperature at 55 °C.The nickel anode plate was hung up and electrolytic treatment was carried out at a current of 0.3A/dm2 for several hours until the cathode turned silver-gray.
8. Take a small amount of plating solution for Hull cell test, add the required nickel sealing additive Ni-351 (without particles), and try plating under normal process conditions.If the test piece is not normal, the plating bath should continue the electrolytic treatment until the test piece is normal.
9. Add calculated Ni-351A brightener, Ni-351B softener and Ni-351C dispersant, stir well, and then slowly add Ni-351D solid particles.After all the additions are completed, the plating solution should be stirred with air for 1 hour to make the particles evenly distributed in the plating solution.
10. After a short period of electrolysis, the plating can be tested, and the workpiece can be put into production when the coating is normal.
In this way, we can correctly formulate the plating solution when using nickel sealing additives to ensure that the workpiece can get a good coating.If you are interested in nickel sealing additives, please contact Bigolly customer service to get free samples and detailed technical information!
If you want to know more about nickel plating, you can check "Electroplating encyclopedia".