Metal finishing Q&As since 1989

-----

Anodize/plating for Al to resist bromides

Is anyone aware of an anodize or plating for aluminum (6061-T651) that would resist the corrosive effects of bromides, specifically HgBr and CsBr. So far I have eliminated a hard chrome anodize and a nickel plating. Interestingly enough, a thin film sulfuric acid anodize has held up quite well, but I have not tested long term exposure as of yet. We are trying to reduce cost in one of our assemblies by eliminating the use of SS.

Thanks,

Marty Verbic
- Urbana, Illinois, USA
 

---

First of two simultaneous responses --

High phosphorous electroless nickel plating will work well for this application.

Todd Osmolski
- Charlotte, North Carolina, USA
 

---

Second of two simultaneous responses --  

Chrome absolutely would not work. Electroplated nickel probably would not be a lot better. Did you try electroless nickel? about 0.001"? That should have worked. If anodize works, I would look for someone that would run it at 65F and about 20 volts. It will be a lot thicker and denser. You might give hard anodizing a try-Say 0.0005 to 0.001 per side.It is much denser.

James Watts
- Navarre, Florida

Check out hard anodising (no seal) followed by thermoplastic impregnation into the pores.

John Tuohy
- Ireland