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  for Metal Finishing since 1989
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Cobalt plating on carbide

I am looking for information about what plating solutions (brand or generic composition) would be best for plating cobalt on sintered tungsten carbide which has a cobalt binder. Cosmetics are not important but the film must be substantially pinhole free.

Jerry Zimmer
sp3 - Mountain View, California
2000

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Jerry, the problem is not so much which plating solution to use as the fact that air can permeate tiny spaces that water can't. If the sintering is less that 100.0000 percent perfect there will be intergranular spaces that won't get plated because plating solutions aren't wet enough. You might want to look into vacuum impregnation first.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2000

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I am assembling a small tungsten carbide piece onto a hardened knurled shaft (approx 1.2 mm). The knurl is employed to attain a very light press fit. It was suggested that copper plating of the carbide ID might be a useful way to permit increasing the tolerances on the hole ID; the idea being the copper, being relatively soft, would accommodate larger fit-up tolerances.

My question is, is it possible to plate copper onto WC? If not copper, are there other materials that could be plated onto the cabide ID (or the shaft OD for that matter)to accomplish this?

Rick Kosarchuk
- Hayward, California, USA
2002