Letter 7077

Information on black nickel plating 

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I have a problem with convincing a colleague about the lack of wear and corrosion resistance of black nickel plating. I have found very little information on the subject, and am hoping someone can direct me in the right direction for wear and corrosion data.

Gregory Selover
- Lex, KY

There may be data available, but I would need to run a literature search to know. But for the down & dirty answer:

There may be other 'black nickel' platings, but the only one I am familiar with is a post-treatment blackening on top of regular nickel plating. Any such coloration topping obviously does not run through the plating, and its thickness is minimal. It couldn't possibly have much wear resistance, even if the material itself were a wear-resistant one, which nickel isn't.

This can be contrasted with black chromium plating, where the material has outstanding wear resistance, and the color runs through the thickness of the deposit.

Ted Mooney, P.E.  finishing.com Brick, New Jersey

Black Nickel is an alloy deposition of nickel and zinc. Corrosion resistance is much worse than pure nickel. I don't know if it is better for wear.

Marcus
- Sachseln

Black Nickel , I have seen some verions of this , under various trade names.

Send some sample to John Schnieder Assoc [Mequon,Wisconsin], they have an excellent black nickel process.

Ron Landrette
plating equipment supplier - Bristol, Connecticut

Although not an answer to the posted question I must point out that (contrary to one respondent's comments) electroformed nickel has excellent wear and abrasion resistance. It is the preferred material for the protection against erosion of the leading edge of helicopter rotor blades and propeller blades. Every manufacturer of helicopters in North America (except Robinson) uses electroformed nickel exclusively for this purpose as do all of the manufacturers of propellers for commuter aircraft.

Rob Housman
- Santa Ana, CA, USA

Thanks Rob. I realize that thousands of different components are built of electroformed nickel. However, this is not exclusively because of the wear resistance of nickel, but it also has a great deal to do with the fact that nickel is so readily electroformable, allowing building of parts of complex and incredibly accurate shape relatively inexpensively.

The particular question had to do with black nickel plating which to the best of my knowledge is just an extremely thin conversion coating on the surface of the nickel plating, and thus I think black nickel is not a wear resistant finish. But I appreciate your criticism and have struck through the closing phrase of my reply. Thanks.

Ted Mooney finishing.com Brick, New Jersey

Hi I have a question about black nickel plating. I never done this before and I'm planning to plate one of my copper bowls with sterling silver rim. I have hammer marks all over my piece and my question is the hammer marks will show up after plating? The hammer marks are pretty deep and sanding it will create a "ding" on the surface. That's my question and I really appreciate your help.

Marisa Widjojo
Art - Seattle, WA

Sorry, Marisa, I don't fully understand your question. If these hammer marks are undesirable scars, no, plating will not fix them -- only sanding and polishing can remove them.

If you are talking, however, about a decorative effect, the plating will not significantly obscure surface texture. However, black nickel or any plating will obscure reflective highlights.

Ted Mooney finishing.com Brick, New Jersey

Does anyone know if the black nickel coating is (electrically) conductive?

Jason Soper
- Guelph, Ontario, Canada

I understand that might be another "down&dirty" way to convincing Gregory S's colleague--try to do the strip-off process for the plating of Black-nickel and other nickel treatment process (for example Electroless Nickel, Bright Nickel...) Compare the process,you will find which plating is more corrosion resistant.
And to do it in a very formal way, do some salt spray test..

NG WEE CHONG
- Kuala Lumpur, Malaysia

May I know the standard pH level, standard temperature, current density and time of black nickel..

Donald Pacis
plating shop employee - Philippines