Summary for hard chrome plating on tungsten Discussion
hard chrome plating on tungsten is discussed as a difficult process, especially when the chrome must be removed and replaced or when a new deposit must survive grinding. Debra Wheeler asked what stripping method would be least likely to etch tungsten and what activation should be used before replating. Ted Mooney replied that the only stripping methods he had heard of were immersion in hydrochloric acid or electrolytic stripping in an alkaline bath, and he believed tungsten is resistant to hydrochloric acid, so that would be the first method to try. In a later question, David P. Ferrairo asked about achieving reliable adhesion for a .010-inch hard chrome deposit on tungsten. Ted said adhesion on tungsten is very difficult and pointed to the ASM Handbook, Vol. 5, Surface Engineering, for a detailed activation and plating protocol for refractory metals like tungsten to maximize adhesion.
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Q. We have some tungsten parts which have been plated with chromium plating. The plating needs to be removed and replaced.
First – What stripping solution/method would be less likely to etch the base material of the tungsten part?
Second – What is the best activation to use for chrome plating on tungsten?
Any information is appreciated.
Thanks,
Debra Wheeler
Southwest United Industries – Tulsa, Oklahoma
2002
Q. We have a direct hard chrome plate requirement .010 thick on tungsten. Does anyone have a reliable method to ensure good adhesion that will withstand post grinding?
David P. Ferrairo
– Seabrook, New Hampshire
2003
“Hard Chromium Plating”
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A. Hello Debra.
I haven’t done it, but the only two methods for stripping chromium that I have ever heard of are:
– Immersion in hydrochloric acid, or
– Electrolytic stripping in an alkaline bath.
My understanding is that tungsten is resistant to attack by hydrochloric acid, so that’s what I’d try until such time as someone with actual experience in it corrects me.
Hi Michael.
There is no question that getting good adhesion onto tungsten is very difficult. However, the ASM Handbook, Vol.5, Surface Engineering has a good chapter on activating and plating refractory metals like tungsten that is worth examining. It’s not so much a quick tip as a protocol for how to do everything possible to maximize adhesion :-)
Good luck!
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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Multiple threads merged: please forgive chronology errors and repetition 🙂
Q. IS THERE A WAY TO STRIP TUNGSTEN CARBIDE, AND CAN YOU HARD CHROME PLATE OVER TUNGSTEN CARBIDE.
THANK YOU
MIKE REED
HARD CHROME PLATING SHOP – SANTA FE SPRING, California
June 29, 2009
A. Hi Mike. As you see, we appended your inquiry to a somewhat similar thread.
Tungsten carbide, however, is not resistant to HCl, so I’d try electrolytic stripping the chrome plating from it in a caustic tank, but not too strong as full strength caustic will also attack tungsten carbide.
Thread 350 suggests that tungsten carbide can be plated with a Wood’s Nickel Strike ⇦ huh? as an initial plating step. If you do try plating the tungsten carbide, please let us know what happened. Thanks.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.