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Electroless Nickel Plating: Colour Change on Component

September 5, 2008

Dear Sir,

We would like to know that during electroless nickel plating on steel components we do heat treatment and we find change in the colour of surface differing to all components .We have a component which has grooves machined on it and we find change of different colours on it. What is the reason behind this activity? Also any literature on this activity.
Thanking You.

Rajan Suri
Product design - India

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Age of bath, chemical ingredients, imbalance and acidic residues left on the surface after complete rinsing tend to cause that effect. Try improving your chemical control of the bath, your rinses (agitation, volume, etc.) and the exposure of plated surfaces to ambient before first rinse and between rinses.

Guillermo Marrufo
Monterrey, NL, Mexico
September 8, 2008

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September 9, 2008

The greatest probability is that the parts are not rinsed well enough. You need multiple counter flowing rinses with DI water to get a uniform color.
Your oven or furnace needs to be clean also.
There is a possibility that you have a trash metal contamination like aluminum which even tho it is electroless, will tend to show up in what would be the low current density areas first and then spread to the entire part as the trash level builds up to a higher level.

James Watts
- Navarre, Florida