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Ted Mooney, P.E. RET
Pine Beach, NJ
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What controls fogginess level of nickel chrome plating?
Q. We are working with two plating suppliers who nickel chrome plate over 17-4 for us. One supplier's parts are shinier than the other. I guess my question is, what controls the shininess or, conversely, the fogginess of NiCr plated parts? It is brightener concentration in the chrome tank? Boric Acid level? I am not a plating expert, so any help would be greatly appreciated. Thanks!
Casey Lee- Hong Kong, Hong Kong
October 12, 2012
A. First strip the chromium by dipping in 1:1 hydrochloric acid.
Rinse and dry. If there is no fog on parts, it means that the problem is in the chromium plating and not in the nickel.
Sara Michaeli
Tel-Aviv-Yafo, Israel
October 22, 2012
A. Hi Casey,
What's the plating thickness of nickel and chromium? Assume you're running trivalent chromium with chromium thickness significantly less than nickel, then nickel deposit should dominate overall brightness.
Nickel deposit brightness is affected by nickel plating additive concentration such as grain refiner, leveler, etc.
Regards,
David
David Shiu
- Singapore
October 21, 2012
A. David,
Most platers still run hexavalent chromium.
The chromium thickness of tri- or hexavalent is max 0.5 micron while the nickel is around 20 microns.
YET, white haze on the parts can still be a result of the chromium layer, not only the nickel.
Sara Michaeli
Tel-Aviv-Yafo, Israel
October 24, 2012
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