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Topography of anodized aluminum

I would appreciate any information regarding how the anodizing process influences the surface topography of an aluminum alloy. After studying samples using a SEM I am interested in reducing the surface roughness by changing the actual anodizing process. Can anyone help or point me in the right direction? Thank you in advance.

William Woolnough
University - Exeter, Devon, UK
2005

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The aluminum on the surface is converted to aluminum hydroxides and other products, which occupy more volume than the original aluminum, so the topography is certainly affected. There are a number of different kinds of anodizing, including phosphoric acid anodizing, chromic acid anodizing, boric acid anodizing, and oxalic acid anodizing in addition to sulfuric acid anodizing. We know what you don't want to do (increase surface roughness more than necessary), but what do you want to do? In other words, why are you anodizing, and what properties are you seeking from the finish?

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005

We anodise primarily for decorative reasons combined with the enhanced protective properties it gives to the surface. At present this is done to BS AA15.

William Woolnough
- Exeter, Devon, UK
2005