Electroplating of nickel-cobalt(1996)
Q. I am looking for someone that could assist me with the process of ELECTROPLATING NICKEL/COBALT AND SILICIUM DEPOSIT. Any companies, services or manufactures involved in the process will be useful in my research. I am waiting for many answers.Carl Bergeron
A. I've no idea about Si-plating.
Anyway, I can assist you with Co-plating. In principle you can use Cobalt sulphamate or sulfate, Boric acid and CoCl2 as the electrolyte.
Concentration of Co is dependent upon the current densities you wish to use. Boric acid: 40 - 60g/l. will be fine and CoCl2 up to 50g/l. will be O.K, pH 3 - 4; T 60 - 70oC.; applying of PR-current and continuous dummying the electrolyte is highly recommended also.
A lot of the literature available on Nickel plating is also valid for Cobalt plating. I suggest you read "Nickel and Chromium Plating" [link is to product info at Amazon] first if you want to do it yourself.
Also the Electrochemical Society should be able to tell you something about Si-plating.
Harry van der Zanden
- Budapest, Hungary
A. Just like Harry, I am unfamiliar with processes to electroplate "silicium." However I have some substantial experience with plating nickel-cobalt alloys.
Unfortunately I have not yet come across any company who offers a proprietary formula for plating NiCo alloy, so we have developed and have always used our own formula for our plating operation. We are using the NiCo as a gold underplate on ceramic packages, and find that adding Co to the nickel layer provides some diffusion resistance effect and also minimizes the formation of problematic nickel-silicide layers which can lead to catastrophic die bond failures in AuSi eutectic die attach systems. These findings have been reported in the literature quite a few times in the past, and are reasonably well understood.
We enjoy pretty good success using an all-sulfate formula in which H3BO3 is the pH buffer component. The bath can operate across a fairly wide pH range of 1.5-4.0, and is best suited for relatively thin coatings (3-5 microns). In our bath, Co plates out preferentially over Ni therefore the solution Co/Ni ratio must be much lower than the intended Co/Ni alloy electrodeposit ratio.
Hope this information helps you. You might also want to check out Abner Brenner's book "Electrodeposition of Alloys" to read about his pioneering work on alloy plating...there is a substantial section covering NiCo alloy electroplating in this book.
Good Luck,Ted Adlam
What are you looking for? Nickel or cobalt, or nickel-cobalt alloy? What is silicium? A typo or trade name? Is the silicium in the plate or on the plate or the plate on it? Might be able to help.
- Navarre, Florida
RFQ: I am looking for plating company which can plate copper parts with 90% Ni (10%)Co.
Size -.140 x .110 x .010
- NYC, New York
We would like to know the name of French or European companies able to apply nickel-silicium coating on hot-forging tools.
Thanks for your help !DUMONT MARCEL
February 12, 2013
Hi Dumont. I see that "silicium" means "silicon" in American english. So I will guess that you are looking for what we call nickel-silicon carbide plating, i.e., nickel plating with particles of silicon carbide occluded in it, which is commonly used for cylinder liners. =>
"Nikasil" is one tradename.
Ted Mooney, P.E.
Pine Beach, New Jersey
I am a young researcher and I am interested in electrodeposition of alloys. How can I obtain the Abner Brenner's book: "Electrodeposition of alloys"?Tutunaru Sebastian Bogdan
- Craiova, Dolj, Romania
It's a quite expensive 2-volume set available from the AESF at www.nasf.org.
Unfortunately, the new printing doesn't seem to be from an actual printing press but from a xerox machine. Although the covers are fine and the paper quality is fine, the pages are faint and in a few places gray or washed out to the point of barely legible. Our copy also has some sections of pages bound out of order, which proves very inconvenient.
If you can find a used copy I think you'll be much happier. Follow the link for possible sources of used copies of "Electrodeposition of Alloys". Good luck.
Ted Mooney, P.E.
Pine Beach, New Jersey
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