The authoritative public forum
  for Metal Finishing since 1989
-----

Is it possible to anodize pure copper?

 

Is it possible to anodize pure copper? If not do you have any other solution. My application is to protect the ID of a water cooled copper nozzle that is subjected to an extremely high temperature Argon, Nitrogen, Hydrogen/Helium gas stream.

Thanking you in advance for your expediance in this matter.

Larry Pollard
Progressive Technologies, Inc. - Grand Rapids, Michigan

---

There is no production of anodized copper to my knowledge, although it has been reported that copper can be anodized in molten KF-HF salts or anhydrous KF-HF mixtures. Correct me if I'm wrong, but aren't Argon and Helium inert gasses that can be omitted from this equation in terms of corrosiveness? I'm not positive about this, but wouldn't chrome plating be promising?

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

For your use, electroless nickel is the optimum and is affordable. It is cheaper if you can plate the entire part with the exception of the contact points. Masking costs more than the EN does in many cases.

James Watts
- Navarre, Florida

To my knowledge, the gases you mentioned are considered inert, ie., they do not readily react. On the contrary, I think you should be more concerned on the water (cooling) side. A wrong pH of cooling water may cause copper corrosion. Iron materials would favor higher pH while copper likes it lower (relatively from iron). I suggest that you consult the water treatment experts on this.

Dado Macapagal
- Toronto, Ontario

It is possible to anodize the pure copper. The result will be a dark layer at the surface with almost no conductivity at the surface.

Babak Zandian
- Mississauga, Ontario, Canada
September 13, 2009