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Dichromate Formation in Anodizing Baths

I need to know if dichromate compounds tie up chromium and make it unavailable for anodizing. Further, are there commonly used available methods for monitoring dichromates in chrome anodizing baths? I am working on an investigation of electrodialysis for bath life extension of chrome anodizing baths, and it has been suggested that the formation of dichromates in the bath by the electrodialysis process could be tying up chromium and making it unavailable for the anodizing reactions. I just received information to this effect and am working under a deadline, and need to suggest lines of research/further analytical work in order to get the project to do the analytical work to develop data to confirm/refute this hypothesis.

James Totter, CEF
- Tallahassee, Florida
2000

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Computerized databases and access to a world-class plating library, is helpful for this kind of project.

I immediately came up with too many hits to pursue, but "The effect of Anodizing Electrolytes on Anodic Alumina Structure and Coating Durability" and "Electrolyte Modifications for Improved Coating Durability on Anodize Aluminum", both by G.A. Dorsey, Jr., Plating, Feb. 69, pp. 177-184 popped up as early studies of the effect of electrolyte ingredients upon chromic acid anodizing.

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