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

Anodising of Al alloys

I'm researching on Al anodising and I have question on the effects of alloying elements. Cu, Si, Mg, Li are often found in Al alloys, what are their effects on anodising? And if the effects are undesirable, is there any treatment that can be done? Also, can Al+ boron carbide composite be anodised?

WY Wong
- Hong Kong
2000

You probably need a book for this one, Mr. Wong, as you question is quite detailed. All of these alloying materials affect the color of the anodized coating. Normally the aluminum is "desmutted" to remove as much of these materials from the surface as practical. There are grades of aluminum that are easy to anodize, grades that are very difficult to anodize (2xxx series), and grades that are impossible.

Without researching it I don't know which class a boron composite falls into, but it would not surprise me if it was the latter.

Regards,

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

---

You do need a book on this subject. The best book I know of is The Surface Treatment and Finishing of Aluminum and Its Alloys by S. Wernick, R. Pinner, P.G. Sheasby. You can also find some interesting websites about this topic. Good luck.

S. Y. Yuen
- Hong Kong, China
2000

Excellent reference.

James Watts
- Navarre, Florida
2000