Nickel plating is a popular surface coating method that has both electrolytic and electroless versions. Let’s look at these versions and four common nickel plating issues and how to fix them.
Standard nickel electroplating involves the use of an electric current to transfer ions between the base metal and the anode, while electroless nickel plating eliminates the need for an electric current by using a plating solution to generate the required chemical reactions.
Common issue 1: Pinholes
Sometimes known as hemp pits, these holes can be microscopic or visible. They can be caused by various things, including organic pollution, poor stirring, metal impurities, incorrect bath temperature, and not using enough boric acid.
To avoid this issue, close attention needs to be paid to the bath concentration and temperature, and stirring must be sufficient to remove any air bubbles. Consider using a wetting agent to help reduce the formation of bubbles and control the ion distribution.
Common issue 2: Brittle coating
If the coating appears brittle, this is usually an indication that there is contamination. This could be heavy metal or organic pollution caused by too many additives.
Again, the main way to avoid this issue is to carefully control the bath, plating solution composition, and processes.
Common issue 3: Roughness
Unexpected roughness on the plating is often a result of a dirty solution that contains impurities. If the current density and/or PH are too high, this can also result in a roughness.
This issue can be avoided by ensuring the plating solution is clean and has the optimal pH, temperature, and current density.
If you need professional help when it comes to nickel plating, specialists such as www.swmf.co.uk/surface-coatings/electroless-nickel-plating can provide advice and services.
Common issue 4: Uneven coating layers
Whilst less of a problem in electroless plating, uneven coating layers can be caused by poor pre-treatment, out-of-range temperatures, and lack of agitation.
To avoid this problem, ensure the temperature of the bath is within the recommended range, and use either mechanical or air agitation to help with ion distribution.